© Reuters / Nacho Doce
Officials may gain access to intimate knowledge of the whereabouts of cell users in Maryland. Phone records could be handed over without a search warrant if a new bill passes. A civil liberties group has labeled the proposal 'invasive'.

The American Civil Liberties Union of Maryland has criticized government plans to allow law enforcement officials automatic access to these records, testifying against the intrusive tracking bill, House Bill 377 , on Tuesday. The bill is currently being considered by the Maryland House Judiciary Committee.

Law enforcement officials must obtain a search warrant prior to accessing such information, insisted ACLUM.

"Of all of the recent technological developments that have expanded the surveillance capabilities of law enforcement agencies at the expense of individual privacy, perhaps the most powerful is cell phone location tracking," said the national American Civil Liberties Union last September, in response to knowledge they obtained that numerous police departments were tracking the devices without a search warrant anyway.

In 2011, cell phone carriers responded to at least 1.3 million actual requests for subscriber information from law enforcement.

Mobile phones register their location with their networks several times a minute, so phone companies already have access to a vast quantity of information regarding details of when users have visited a certain place.

"Personal and often private information can be revealed by cell phone location tracking...the stakes are enormous," said ACLUM

Law enforcement officials say that it is not overly invasive, and could aid in locating the whereabouts of a missing child.

Many have pointed out that the bill comes into direct conflict with the Fourth Amendment right to privacy, and its passage could pave the way for wider state legislation that comes into direct conflict with federal law. Bills passed in individual states can often set a precedent and instigate future bills in other states.

In January 2012, in US v Jones, the Supreme Court ruled that the attachment of a GPS device to a vehicle "constituted a search under the Fourth Amendment." It was declared unconstitutional to engage in similar tracking procedures without a search warrant, as the process of tracking someone's movements through GPS was considered a similar practice to that of a search.

A bill to stop software developers secretly spying on the users of smart phone applications was also introduced by the US Senate Judiciary Committee in December 2012.Concerns were aired that there were few laws in place limiting how phone companies could use all the location data they amass.