It wasn't long after he met the man called Shareef that Khalifa Al-Akili began to sense he was being set up. Within days of their seemingly chance meeting, Shareef was offering to drive Akili, a 34-year-old Muslim living in East Liberty, Pennsylvania, to the local mosque for prayers. Shareef told Akili he was "all about fighting" and "had a lot of resources at his disposal." But when Shareef began to probe Akili about his views on jihad and asked him if he could obtain a gun, Akili grew nervous. "I begin to try to avoid him, but would still see him due to the fact that he lived two minutes' walking distance from my apartment," Akili said later. In January of this year, Shareef showed up with a "brother" who called himself Mohammed and was keen to meet Akili. Mohammed told Akili that he was a businessman from Pakistan involved in jihad. "He kept attempting to talk about the fighting going on in Afghanistan, which I clearly felt was an attempt to get me to talk about my views," Akili recalled. "I had a feeling that I had just played out a part in some Hollywood movie where I had just been introduced to the leader of a terrorist sleeper cell."

Out of curiosity, Akili did an Internet search on the cellphone number he'd received from Mohammed. Much to his surprise, he discovered that the man was, in fact, an FBI informant named Shahed Hussain, who had played a pivotal role in at least two major terrorism-related sting operations in recent years. In a lengthy posting on his Facebook page recounting these events, Akili wrote, "I would like to pursue a legal action against the FBI due to their continuous harassment." He also set up a press conference in Washington with Muslim civil liberties groups to publicize his fear that he was being entrapped. But it was too late. In mid-March, Akili was arrested and charged with being in possession of a .22-caliber rifle at a shooting range several years earlier, an act deemed illegal because of a decade-old drug conviction. Though his arrest was on nonterrorism-related charges, at his bond hearing FBI agents and US Attorneys told the judge they'd seen unspecified "jihadist literature" at his apartment and also alleged that he'd told one of the informants of his desire to go to Pakistan and join the Taliban. The judge ordered Akili held without bail.

"The government is basically saying [the charges have] nothing to do with the informant," Akili's attorney, Markéta Sims, told me. "But I've been doing this a long time, and I've never heard of someone being charged with felony possession for handling a gun at a shooting range."

The FBI has employed informants ever since its inception as the Bureau of Investigation in 1908. In 1961 director J. Edgar Hoover established the Top Echelon Criminal Informant Program, in which FBI field offices were instructed to develop live sources in the "organized hoodlum element." By 1975 the Church Committee found that the bureau was employing more than 1,500 domestic informants. But while the FBI has long used undercover informants to infiltrate criminal networks and build cases against potential suspects, in the domestic front of the "war on terror," informants have come to play a far more proactive role in surveilling communities deemed suspect by the bureau.

According to the Center on National Security at Fordham Law School, there have been 138 terrorism or national security prosecutions involving informants since 2001, and more than a third of those have occurred in the past three years. Nearly every major post-9/11 terrorism-related prosecution has involved a sting operation, at the center of which is a government informant. In these cases, the informants - who work for money or are seeking leniency on criminal charges of their own - have crossed the line from merely observing potential criminal behavior to encouraging and assisting people to participate in plots that are largely scripted by the FBI itself. Under the FBI's guiding hand, the informants provide the weapons, suggest the targets and even initiate the inflammatory political rhetoric that later elevates the charges to the level of terrorism.

Before he approached Akili, Hussain was pivotal in securing convictions in 2006 against two Muslim men in Albany, New York - an imam and a local pizza shop owner. He had lured the two into a loan transaction that prosecutors later alleged was a deal to launder the proceeds of an illegal missile sale, though neither man had any prior criminal record or history of violence. In a separate case in 2008, Hussain was dispatched to Newburgh, New York, where he spent nearly a year enticing a group of indigent African-American and Haitian men, some of whom converted to Islam in prison, with offers of as much as $250,000 to participate in a plot to bomb a Bronx synagogue and Jewish community center. After the men were convicted at trial, the judge in the case, Colleen McMahon, said it was "beyond question that the government created the crime here" and criticized the FBI for sending informants "trolling among the citizens of a troubled community, offering very poor people money if they will play some role - any role - in criminal activity." The men were sentenced to twenty-five years in prison.

The FBI's expanded deployment of informants over the past decade is the result of a mandate to catch terrorists before they can strike next, an effort that has fundamentally refocused the bureau from its traditional law enforcement mission to gathering intelligence on potential threats. Within a year of the 9/11 attacks, the FBI had reassigned nearly half its field office positions formerly devoted to the "war on drugs" to the new "war on terror" and launched nearly 3,000 new counterterrorism investigations. Since then, the bureau has been increasingly devoted to counterterrorism efforts: its current $8.1 billion budget allocates $4.9 billion to intelligence and counterterrorism, approximately $1.7 billion more than all other federal crimes combined.

Informants are crucial to producing the raw field intelligence that the bureau uses to justify these vast new expenditures. Under the FBI's Domain Management program, modeled after the NYPD's CompStat initiative, FBI Director Robert Mueller holds periodic "accountability" meetings with field offices, in which his agents report on a series of intelligence-gathering metrics in the geographic areas they oversee - among them the production of raw intelligence gathered by informants or electronic surveillance compiled in "information reports" and disseminated to law enforcement agencies. These informants operate in a post-9/11 environment of relaxed guidelines that allow the FBI to engage in lengthy and extensive surveillance of individuals and communities with little or no evidence of any wrongdoing afoot. Where once agents needed to have a "predicate" to launch such an investigation, these days none are required.

The FBI has kept the details of the full scope of its informant network a closely guarded secret. It has not revealed the number of official and unofficial informants (the latter known as "hip pockets" in bureau parlance) on its payroll; or how much it budgets for these informants; or what kinds of targets they track, particularly in Muslim communities. In its 2008 budget request the FBI disclosed that it had been working since November 2004 under a classified presidential directive that mandated an unspecified increase in "human source development and management." In 2009, after civil liberties groups sued for some of these details under the Freedom of Information Act, the bureau made public its internal investigative guidelines but redacted nearly the entire section on "undisclosed participation" of confidential informants.

Though relatively few informant-driven investigations have led to the discovery of actual "homegrown" plots, the Muslim community for years has reported instances of people being approached by informants trying to enlist them in violent jihad. At times the informants have been so aggressive they have quickly raised suspicions. At a California mosque in 2010 one FBI informant, Craig Monteilh, advocated violent jihad so vehemently that the mosque's members sought and received a restraining order against him. Monteilh, a former fitness instructor paid $177,000 over the course of his service with the FBI, participated in what the bureau dubbed Operation Flex, in which he was assigned to monitor gyms and mosques across Orange County, California, home to the country's second-largest Muslim population. "We started hearing that he was saying weird things," college student Omar Kurdi later told a reporter. "He would walk up to one of my friends and say, 'It's good that you guys are getting ready for the jihad.'"

Once the restraining order was issued, Monteilh was effectively done as an informant. His work became public a few months later when he was convicted on grand larceny charges in an unrelated incident. He subsequently sued the FBI, alleging the agency had revealed his informant status, leading to an attack by a fellow prisoner during his incarceration. He also gave a statement in support of a suit filed against the bureau by the ACLU that named the then head of the Los Angeles office, J. Stephen Tidwell, who had made a point of visiting a mosque in Irvine in June 2006 and telling the congregants that the FBI would not spy on them. "If we're going to mosques to come to services, we will tell you," he said. "We don't want you to think you're being monitored. We would come only to learn." The next month, agents under Tidwell deployed Monteilh to the very same mosque.

According to Monteilh, his handlers in Operation Flex instructed him to identify potential militants or, failing that, to "pay attention to people's problems" - such as marital or business difficulties - and assess whether individuals might be susceptible to rumors about their sexual orientation "so that they could be persuaded to become informants." His handlers also told him that "everybody knows somebody," meaning that people from Afghanistan, for example, would inevitably have family members or acquaintances with ties to the Taliban - information the FBI could use to "threaten...and pressure them to provide information, or could justify additional surveillance." Monteilh said the agents also gave him the green light to have sex with Muslim women for investigative purposes. "They said if it would enhance the intelligence, go ahead and have sex," he told a reporter. "So I did." When Monteilh asked his handler, agent Kevin Armstrong, about the FBI's broad latitude in conducting the investigation, he said Armstrong told him that on national security matters, "Kevin is God."

In 2005 the FBI's Office of the Inspector General found "serious shortcomings" in the bureau's Criminal Informant Program. The report, which examined some 120 cases, including those related to terrorism, found that 87 percent of the investigations involving informants contained violations of the FBI's own guidelines. Among the chief violations were the failure of agents to caution informants about the "limits of their activities," the "failure to report unauthorized illegal activity" by their informants, and the issuance of "retroactive approvals" for illegal acts the informants had already committed. The report noted that since 2001 the rules had been loosened at the FBI's request to reflect the new emphasis on intelligence gathering, and by extension the bureau's dire need for informants. In testimony before Congress in May 2002, FBI Director Mueller argued that requiring agents to read "verbatim instructions" to their informants, "written in often intimidating legalese, [was] proving to have a chilling effect, causing confidential informants to leave the program."

When inspectors asked the FBI to identify a terrorism investigation in which an informant had played a "pivotal role," the bureau cited the work of Mohamed Alanssi, who in 2005 had secured the conviction of a well-known Yemeni cleric and his assistant. The two men were charged with funding Al Qaeda and Hamas. What the report didn't mention was that Alanssi, in a fit of pique at his handlers (who he claimed owed him money for his services as an informant in as many as twenty terrorism prosecutions), had set himself on fire in front of the White House and ended up being deemed so unstable that at the trial of the two Yemenis, he was asked to testify for the defense.

For Muslims approached by the FBI to become informants, the consequences of declining such requests can be dire. Ahmadullah Niazi, one of the mosque members who reported the FBI's own informant, Craig Monteilh, after hearing him talk about planning a terrorist attack, was later contacted by agents and asked to become an informant himself. When he refused, he found himself arrested on charges of lying to immigration officials after he allegedly denied having family ties to a member of Al Qaeda. Prosecutors ultimately withdrew the charges, but Niazi said by the time the case was dismissed, both he and his wife had lost their jobs.

In 2010 Tarek Saleh, a Brooklyn cleric, alleged that the FBI derailed his green card application after he declined its request to travel to Afghanistan and make contact with a relative who was allegedly part of Al Qaeda. "To use me as a bait to trap people, I cannot do this job," Saleh said.

Tarek Mehanna, a 29-year-old US citizen convicted this year of advocating violent jihad through his writings and translations of various texts, claims that the criminal case against him was initiated after he rebuffed the overtures of FBI agents to become an informant. "They said that I had a choice to make: I could do things the easy way or I could do them the hard way," Mehanna said at his sentencing. "The 'easy' way, as they explained, was that I would become an informant for the government, and if I did so I would never see the inside of a courtroom or a prison cell. As for the hard way, this is it."

With the FBI's expanding operations overseas, such cases are not limited to the United States. In one instance in 2010, FBI agents and other American officials contacted Yonas Fikre, a Muslim American from Portland, Oregon, while he was visiting family in Sudan. Fikre declined to be questioned without a lawyer present and rejected a request to become an informant. He subsequently received an e-mail from a State Department address: "Thanks for meeting with us last week in Sudan. While we hope to get your side of the issues we keep hearing about, the choice is yours to make. The time to help yourself is now." A year later, while traveling in the United Arab Emirates, Fikre was arrested by local security forces, who detained and tortured him for three months, he alleges, asking many of the same questions the FBI had posed to him. One of his interrogators told him he was being held at the behest of the United States.

Attorneys at the CLEAR (Creating Law Enforcement Accountability & Responsibility) project, based out of the City University of New York School of Law, have represented dozens of people since 2009 who have been approached by the FBI for voluntary interviews; they say the threat of retribution for those who refuse to become informants is real. "The FBI approaches the vast majority of our clients as potential informants to partake in mass surveillance of Muslim communities, unconnected to any real criminal investigation," said Amna Akbar, a supervising attorney at CLEAR. "The bureau is aggressively attempting to cultivate informants in Muslim communities by using coercion, pressure tactics and intimidation."

As an example, Akbar cites the case of Mohammed Tanvir, a 28-year-old from Pakistan who in October 2010 found himself on the Department of Homeland Security's "no fly" list following more than a year of fending off requests from FBI agents to become an informant. In 2009, after returning from a visit to his wife in Pakistan, Tanvir says agents appeared at a 99 Cent Store in the Bronx where he worked to question him. "They said they had been following me," Tanvir recalled. "They had photos of me riding the train to work." The agents told Tanvir they'd heard from his co-workers at a previous construction job that he had been to Taliban training camps in Afghanistan, a claim Tanvir denies; he says that Indian immigrants at the worksite called him "Taliban" to taunt him about his Pakistani nationality. The agents nevertheless pressed him to become an informant, asking him to focus on the South Asian community in New York City, and offered him money and other enticements, such as bringing his wife to the United States and paying for his parents to make religious pilgrimages from Pakistan to Saudi Arabia. "We need people like you to just watch around your community," Tanvir says the agents told him. He also says they wanted him to go to Afghanistan to infiltrate militant training camps and "report on what is going on there." Tanvir, who insists he has no knowledge of the training camps, declined the FBI's request despite threats that he would be deported back to Pakistan - a prospect that frightened him because his family depended on the money he was sending from the United States.

Tanvir says the FBI first approached him in 2007, after he wired money to help a childhood friend from Pakistan who had been detained in Mexico for overstaying his visa. At the time the agents merely questioned him, but once they'd set their sights on him as a potential informant, he says they called him repeatedly, showed up at his workplace, and threatened to arrest him if he refused to take a polygraph and undergo further questioning. Eventually, Tanvir says, he stopped taking their calls.

Akbar says the FBI placed Tanvir on the "no fly" list as retaliation for his refusal to work as a paid informant. In May CLEAR sent a letter to the FBI threatening to sue if Tanvir isn't removed from the list. Regardless of the outcome, Tanvir - a green card holder who once hoped to settle in the United States - says that as a result of his ordeal, he is now seeking to return to Pakistan permanently.