© Vincent Kessler / ReutersFormer U.S. National Security Agency contractor Edward Snowden.
NSA whistleblower Edward Snowden said that the FBI's claim to need Apple to unlock the iPhone a San Bernardino shooter is a sham.

The FBI says that only Apple has the ability to crack the work phone left behind by the San Bernardino terrorists, and last month convinced a federal judge to compel the tech giant to write a custom operating system with intentionally weakened security mechanisms. Apple is refusing to do so, and said that it is willing to take the fight to the Supreme Court.

Over a video link appearance at Blueprint for a Great Democracy conference on Tuesday, Snowden took Apple's side.

"The FBI says Apple has the 'exclusive technical means' to unlock the phone," Snowden told the audience from Moscow."Respectfully, that's horse sh*t."

Snowden later tweeted a link to an American Civil Liberties Union blog post titled "One of the FBI's Major Claims in the iPhone Case Is Fraudulent," which argues that the government doesn't actually need Apple's help to bypass the "auto-erase" feature on the iPhone in question.

This sentiment echoes that of many tech experts, as well as some lawmakers.

At a hearing last week, Representative Darrell Issa, a California Republican who made his fortune in electronic car alarms, asked FBI Director James Comey if he considered the possibility of creating enough copies of the phone's data to try hundreds of passwords. Apple likely wouldn't have objected to this simple method, and the FBI couldn't answer why they didn't consider it.

Comey also acknowledged that the FBI made the mistake of changing the iCloud password on Farook's account, security researcher Jonathan Zdziarski wrote in a blog post.

"In other words, the mistake of trying to break into the safe caused the safe to lock down in a way that made it more difficult to get evidence out of it," Zdziarski said.

Snowden has previously applauded Apple for its defense of privacy and strong encryption, even before their current battle with the FBI.

"We should support vendors who are willing to [say], 'You know, just because it's popular to collect everybody's information and resell it to advertisers and whatever, it's going to serve our reputation, it's going to serve our relationship with our customers, and it's going to serve society better. If instead we just align ourselves with our customers and what they really want, if we can outcompete people on the value of our products without needing to subsidize that by information that we've basically stolen from our customers'," he told TechCrunch in June, months before the December massacre in San Bernardino. "That's absolutely something that should be supported."