The digital rights advocacy group Electronic Frontier Foundation (EFF) announced Thursday it had discovered violations stemming from the FBI's use of expiring provisions of the USA PATRIOT Act.

Documents obtained by the group as the result of pending Freedom of Information Act litigation suggest that abuses of surveillance powers granted by the PATRIOT Act had been flagged by the FBI.

Congress passed a bill in February that extended the roving wiretap, "lone wolf" and "library records" provisions of the PATRIOT Act until May 27. The three provisions allow authorities to conduct surveillance without identifying the person or location to be wiretapped, permit surveillance of "non-US" persons who are not affiliated with a terrorist group, and allow law enforcement to gain access to "any tangible thing" during investigations, respectively.

FBI Director Robert Mueller told members of the Senate Judiciary Committee on Wednesday that the three provisions should be made permanent. He also told the committee he was "not aware of any" abuses resulting from the provisions.

Among the heavily-redacted documents obtained by the EFF is a report [PDF] showing that the FBI monitored young children for five days, despite the fact that none of the voices being monitored matched the language of the target. The report concluded that the roving wiretap violation occurred as a result of an inadequate review of the wiretap renewal application.

The documents were obtained as part of the EFF's ongoing FOIA Litigation for Accountable Government (FLAG) Project.

Congress is expected to pass a longer extension of the three controversial provisions of the PATRIOT Act, but some senators have vowed to amend the legislation to ensure American's civil liberties are protected.

Senate Majority Whip Dick Durbin (D-IL) has proposed an amendment to the bill that would require the government to describe the target of a roving wiretap "with particularity."

"Roving wiretaps, which do not require the government to specify the place to be bugged, are designed to allow law enforcement to track targets who evade surveillance by frequently changing phones," he explained. "Before the PATRIOT Act, roving wiretaps were only permitted for criminal investigations."

"Unfortunately, the PATRIOT Act did not include sufficient checks to protect innocent Americans from unwarranted government surveillance," Sen. Durbin continued. "Under current law, the FBI is not required to ascertain the presence of the target of the wiretap at the place being wiretapped, as it is for criminal wiretaps."