The ACLU released information from the IRS 2009 handbook obtained through a Freedom of Information Act request Wednesday.
In it, the IRS says the Fourth Amendment doesn't protect emails or texts because Internet users "do not have a reasonable expectation of privacy in such communications."
The IRS cites the Electronic Communications Privacy Act of 1986, which states government officials only need a subpoena to read emails that have already been opened or are more than 180 days old, The Hill reported. The subpoena would not require a judge's approval.
The ACLU said the Fourth Amendment provides greater privacy than the IRS and ECPA say, and that all officials should have to obtain a warrant to access such information.
Lawmakers are currently working on legislation that would update ECPA to require a warrant to obtain private online messages, The Hill reported.