Documents, obtained by ACLU after months of litigation, reveal that there has been a whopping 361 per cent increase in “pen register” and “trap-and-trace” orders between 2009 and 2011.

Pen register and trap and trace devices, which were a lot more invasive surveillance tools, about two decades ago have taken a new form wherein no special equipment are required to record information. Today, such interception capabilities are already built into the call-routing hardware itself.  Pen registers capture outgoing data as compared to trap-and-trace that captures incoming data, which may include email addresses, phone numbers of incoming and outgoing calls, duration of those calls, etc. None of these surveillance techniques are supposed to record the content of the communication.

Naomi Gilens, legal assistant with ACLU writes in a blog post, “more people were subjected to pen register and trap-and-trace surveillance in the past two years than in the entire previous decade.”

ACLU revealed that US law enforcement agencies, back in 2009, managed to obtain 250 pen register orders and 200 trap-and-trace orders, while the number stood at 800 for each of the order types in 2011. ACLU has appealed to US congress to bring in more judicial oversight of pen register and trap-and-trace orders the reason being pen register and trap-and-trace orders don’t require a warrant and the concerned law enforcement agency can procure the order by submitting a certification to a court stating that they seek information relevant to an ongoing criminal investigation.