Quoting from Declan Mccullagh's excellent post at CNET;
For criminal investigations, police are generally required to obtain a wiretap order from a judge to intercept the contents of real-time communication streams, including e-mail bodies, Facebook messages, or streaming video. Similar procedures exist for intelligence investigations under the Foreign Intelligence Surveillance Act, which has received intense scrutiny after Edward Snowden's disclosures about the National Security Agency's PRISM database.But there is a loophole called a pen register and trap and trace order with minimal judicial review or oversight. Here statue and precedents have not kept up with technology. Do judges know what the hell they a doing when okay a trap and trace order? Even if we assume the best and concede that all judges, both FISA and conventional, are assiduously protecting the fourth amendment how do we know that in era of rapidly emerging technology they know what they are doing? Judges assume that they have almost no right to stop pen register request. "The court under the Act seemingly provides nothing more than a rubber stamp," wrote a federal magistrate judge in Florida, referring to the pen register law.
So far it's not known how many if any internet providers have caved to the FBI's demands. They are acutely aware that they may be vulnerable to lawsuits. In the mean time maybe we could raise money and hire Edward Snowden to set up a farm of proxy servers in Russia, while we all migrate to open source Linux on our personal machines. Oops! forgot that jail breaking a cell phone is still illegal.