The Internal Revenue Service (IRS) has claimed that agents do not need warrants to read people's emails, text messages and other private electronic communications, according to internal agency documents.
The American Civil Liberties Union (ACLU), which obtained the documents through a Freedom of Information Act request, released the information on Wednesday.
In a 2009 handbook, the IRS said the Fourth Amendment does not protect emails because Internet users "do not have a reasonable expectation of privacy in such communications." A 2010 presentation by the IRS Office of General Counsel reiterated the policy.
Under the Electronic Communications Privacy Act (ECPA) of 1986, government officials only need a subpoena, issued without a judge's approval, to read emails that have been opened or that are more than 180 days old.
Privacy groups such as the ACLU argue that the Fourth Amendment provides greater privacy protections than the ECPA, and that officials should need a warrant to access all emails and other private messages.
Traditionally, the courts have ruled that people have limited privacy rights over information they share with third parties. Some law enforcement groups have argued that this means they only need a subpoena to compel email providers, Internet service companies and others to turn over their customers' sensitive content.
But in 2010, a federal appeals court ruled that police violated a man's constitutional rights when they read his emails without a warrant.
Despite the court decision, U.S. v. Warshak, the IRS kept its email search policy unchanged in a March 2011 update to its employee manual, according to the ACLU.
In an October 2011 memo obtained by the ACLU, an IRS attorney explained that the Warshak decision only applies in the Sixth Circuit, which covers Kentucky, Michigan, Ohio and Tennessee.
But the attorney noted that if a service provider fought the search request, it would likely result in "protracted litigation," meaning that any leads from the emails would be "stale" if the IRS ever obtained them.
The IRS did not respond to a request to comment.