Adding to a growing list of similar rulings over the past few years, a Missouri federal judge today ruled that the FBI did not need a warrant to secretly track a suspect's car for two months. The Supreme Court is set to rule in a similar case within the next few months in US v. Jones. 

As Threat Level points out, the Missouri judge's ruling today echoes the Obama administration's arguments at the Supreme Court for warrantless GPS tracking: suspects have no right to privacy in public. Civil liberties groups, privacy advocates and some judges disagree. 

A particularly eloquent decision against warrantless GPS tracking was written when the issue came before the US Court of Appeals of the DC circuit. Writing for the majority, Judge Douglas H. Ginsburg described why this kind of warrantless tracking is dangerous to our democracy:

A person who knows all of another's travels can deduce whether he is a weekly churchgoer, a heavy drinker, a regular at the gym, an unfaithful husband, an outpatient receiving medical treatment, an associate of particular individuals or political groups—and not just one such fact about a person, but all such facts.

Read more about the Jones case. Read the Missouri court's ruling.