Justice Department reports recently revealed by the ACLU show a dramatic increase in electronic surveillance, suggesting yet again that it's become common practice among law enforcement agencies. The ACLU surveyed three years of reports from the Attorney General, recording when the Department of Justice asked for pen register or trap and trace surveillance. Unlike a wiretap, these methods don't record the content of an email or phone call — instead, they collect metadata like the phone numbers being dialed or recipients of emails. That makes them more innocuous in some ways, but it also means that the bar for justifying them is lower. And "non-content information," the ACLU says, "can still be extremely invasive."

Phone surveillance orders increased 60 percent between 2009 and 2011The ACLU found that between 2009 and 2011, orders for phone surveillance increased 60 percent, while email and other internet orders quadrupled in the same period of time. Phone monitoring is still much more common, with about 38,000 total phone orders in 2011 compared to under 2,000 for internet. Phone orders are also affecting a much larger group than before: over three times as many people were targeted last year than in 2009. Requests from other agencies, like the Department of Homeland Security, also aren't included on the list, nor are local police departments.

"Non-content information can still be extremely invasive."It's not guaranteed that the reports include every Department of Justice request, but these numbers fit with those of overall phone surveillance, which has been increasing steadily over the past five years. Law enforcement agencies have argued before that electronic surveillance allows them to cover more ground with fewer officers or update traditional methods with high-tech counterparts, claims that do have merit. The easier it is to monitor communications, however, the easier it becomes to erode privacy.

Although the ACLU criticizes the Department of Justice for obscuring its reports, this is still more information than we've received elsewhere. The National Security Agency has consistently refused to disclose the extent of its own monitoring activities, and Congress recently passed an extension to the FISA Amendments Act of 2008, which broadens the permissions for wiretapping without a warrant and makes it less likely we'll know just how widespread the practice is.