4. Misuse of the Patriot Act (Department of Justice IG, 2008)
In 2008, after several lawsuits about the FBI’s use of National Security Letters, the Department of Justice (DOJ) IG released a report confirming that under the controversial Patriot Act, the FBI was abusing its power to force the disclosure of customer records held by banks, telephone companies, and Internet providers. The audit found that these National Security Letters "were issued without proper authority, cited incorrect statutes or obtained information they weren't supposed to," according to CNN. This wasn’t the only DOJ IG report to reveal these kinds of abuses—a 2010 report showed that the FBI was skirting laws by obtaining phone records through post-it notes.
Image of old-school phone by Flickr user plenty.r.