The rest of your comment saps your credibility.
"Some pissed off cop can just" &c &c &c --- well, let's not discuss what the police should be able to do at all then, because this is logic that inevitably ends up with us throwing up our hands. Or, because we're on Hyperbolic News, having a debate about whether the citizens of a truly free society need police at all.
"The administration, which is attempting to overturn a lower court ruling that threw out a drug dealer’s conviction over the warrantless use of a tracker, argues that citizens have no expectation of privacy when it comes to their movements in public so officers don’t need to get a warrant to use such devices."
I don't immediately see why that wouldn't apply to law enforcement cars in public, as well. It would be a boon to criminals, though, unfortunately. (Hm, which now makes me wonder if it could be happening already by more advanced criminal organizations?)
Only if it were real-time. If there were a 7 day lag on the data being publicized it would prove the point without giving the possibility of using the data to evade police in the moment.
[1]: http://web.mit.edu/newsoffice/2003/gia.html
[2]: http://www.theinquirer.net/inquirer/news/1011439/mit-launche...
And on this note... does anybody actually know what happened to the original GIA site? Did they just get bored with the idea, or were they pressured into shutting it down, or what?