A new battleground has opened up in the war over who has access to our electronic data trails: legislation is now being debated in states across the country to require a warrant for law enforcement access to location information in criminal investigations. The biggest roadblock these bills are facing? Attempts to reduce their protections to cover only "real-time" location tracking, leaving inconsistent and often completely absent rules governing law enforcement access to "historical" data.

We've seen laws enacted in two states so far: Montana and Maine . Both cover real-time and historical location information, although Maine's bill explicitly mentions historical data, while Montana's is implicitly inclusive (it simply talks about location information with no temporal reference).

Ohio , Massachusetts , Minnesota , Missouri , New Hampshire , South Carolina , Tennessee , and Utah are among the states currently moving bills that cover both real-time and historical location information. The Virginia legislature recently sent a real-time-only bill to their governor's desk, and Illinois is working on a real-time-only bill.

We feel very, very strongly that bills must be inclusive of real-time and historical location information. Here's why:

Where you were two minutes ago, two months ago, or two years ago can be no less sensitive than where you are now. In fact, it may be more sensitive because it shows patterns of behavior over time. The fact that I go to a particular house tonight may not mean anything; if I go to that house every night, it may be where I live or where my partner lives, or where I'm having an affair.

And, not only does historical information expose patterns and past activities, it can be, for all practical purposes, real-time information: If you know where I was ten seconds ago, or even ten minutes ago, you more or less know where I am right now. A bill that limits only "real-time information" but not historical information would likely fail to meaningfully protect present location. Case in point: there is a documented track record of law enforcement agencies evading restrictions on real-time tracking by, for example, arguing that a request for real-time location information is actually a request for historical information because it may take a few seconds for wireless carriers to transmit a phone's current location information to the police.

Only a fraction of tracking is real-time tracking—and that fraction is shrinking.

We are working hard in states across the country to pass truly protective location privacy laws – and that means also working to defeat these phony bills, which give the illusion of protection and threaten to put the issue to bed while allowing law enforcement to continue their invasive tracking practices practically unfettered. Where you go says a lot about you, and law enforcement should only be getting that sensitive information if there's good reason to believe it will turn up evidence of a crime. Any new legislation must be measured against this standard. As with many issues, our state-level work on location tracking is an end in and of itself, but we also hope that good state-level legislation will build momentum for good federal level, nationwide fixes .

Watch this video to learn more about what law enforcement might be able to do with all that data: