Civil liberties group the Electronic Frontier Foundation says it has unearthed upwards of 40,000 intelligence violations relating to investigations carried out by the FBI.
In a report released today the EFF says that the Federal Bureau of Investigation has "compromised the civil liberties of American citizens far more frequently, and to a greater extent, than was previously assumed."
The revelations in the report were unearthed in documents obtained by the EFF using Freedom of Information Act Litigation and show that the Intelligence Oversight Board, which is supposed to protect the public from FBI abuses, takes on average two-and-a-half years to report violations.
The documents have also revealed cases of serious misconduct by Federal agents including perjury, using dodgy evidence to obtain grand jury subpoenas and illegally accessing password-protected files without a warrant.
In all, the documents expose as many as 40,000 possible violations between 2001 and 2008.
The report (PDF) is based on close to 2,500 FBI documents sent to the Intelligence Oversight Board, a supposedly independent civilian organisation which is charged with reporting abuses of intelligence powers directly to the President.
The EFF says the report underscores the need for "greater transparency and oversight in the intelligence community" and that it will be sending copies of the report to members of Congress.