The idea of IRS agents poking through your email account might sound at the very least creepy, and maybe unconstitutional. But the IRS does have a legal leg to stand on: the Electronic Communications Privacy Act of 1986 allows government agencies to in many cases obtain emails older than 180 days without a warrant.

That's why an internal 2009 IRS document claimed that "the government may obtain the contents of electronic communication that has been in storage for more than 180 days” without a warrant.

Another 2009 file, the IRS Criminal Tax Division's "Search Warrant Handbook," showed that the division's general counsel believed "the Fourth Amendment does not protect communications held in electronic storage, such as email messages stored on a server, because internet users do not have a reasonable expectation of privacy."

In December 2010 the Sixth Circuit Court of Appeals ruled that just because your email goes through a third-party service provider doesn't mean you lose that expectation of privacy. It said federal and local law enforcers would need a warrant to read through the contents of email.

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.