As Congress returns from its August recess, one big item on its to-do list will be to update the Electronic Communications Privacy Act. Amendments to the 27-year-old statute passed the Senate Judiciary Committee earlier this year, but there's been no further progress on updating the law that lets federal investigators seize e-mail records without a warrant.

Now, a bunch of states are taking matters into their own hands, with each considering (or  already settling on) legislative language that makes it harder for state and local law enforcement to read unopened e-mails, as well as e-mails that have sat unopened in an inbox for more than 180 days.

Texas was the first state to pass such a bill. In June, Gov. Rick Perry signed HB 2268 into law, instantly making the former Republican presidential candidate one of the country's most progressive figures on electronic privacy.

In Montana, an e-mail and location-tracking privacy bill known as HB 603 became law in May after being passed in the state legislature with virtually no opposition.

Allie Bohm, a policy analyst at the ACLU, said that not even law enforcement officers objected to the law. Montana's traditional views on privacy are so strong that many police officers request a warrant even if the law doesn't require it. When the state Senate House passed the bill by a 92-vote margin in April, many Montanans had no idea they had become pioneers in privacy law.

"It was a really interesting conversation to have with them because they actually didn't know they were first in passing a location-tracking bill," said Bohm. "They were like, 'Wow, if we'd known it was historic, we'd have checked in sooner!' It was really such a no-brainer to them that they figured somebody else must have it already."

Maine passed a reform bill that might be considered "privacy-lite," with lawmakers approving legislative language that addressed text messages by requiring warrants to get access to their contents. That could limit how far the state privacy law can go in protecting other forms of electronic communication. But the legislature also took on the issue of geolocation data, overriding the governor's veto to pass a law requiring police to obtain a warrant in order to track the location of a cellphone or other electronic device.

New York and Florida lawmakers are preparing privacy bills for their 2014 legislative sessions. And in Massachusetts, whose legislature meets year-round, lawmakers recently held a hearing to consider a bill that tackles both e-mail privacy and geolocation data generated by mobile devices. (Here are the state bill's Senate version and House version.)

But state-level laws cover only state-level authorities and can't compel federal investigators. For that, there must be congressional action.

If the Massachusetts effort is successful, however, that could set an important example for Washington on how to legislate on privacy issues, Bohm said.

"It's like, 'If you can get this through, you can show Congress how to do ECPA reform,'" she said.