A new bill introduced today in the US House of Representatives seeks to require warrants before police can trawl through your e-mail or track your cell phone, reports CNET. The legislation is backed by several technology companies, including Apple, Google, Microsoft, and Twitter. But given the government's history with privacy bills, it faces a high chance of getting blocked by the Department of Justice.

The bill was introduced by Representative Zoe Lofgren (D-CA) and would require officers to get a warrant before accessing e-mail or location information. Access to these data types is a notorious gray area in US courts.

In August, the US Circuit Court of Appeals for the Sixth Circuit ruled that law enforcement officials were within their right to access the location data from a man's cellphone without a warrant. The basis for this ruling was the Stored Communications Act, which states authorities may not access the content of communications, but are allowed to see where and to whom they went. Prosecutors have been using this law to justify access to location data for some time, but the interpretation has been increasingly called into question by civil liberties groups.

Lofgren's bill would amend the Electronic Communications Privacy Act that went into effect in 1986—the olden cellular days, before even Zach Morris had GPS in his phone. Such bills in the past have been blocked by the Department of Justice on the grounds that making access to information in the cloud and on cellular networks would make police investigations more difficult; this one may face a similarly unsuccessful road.