Kenneth Roth writes: As a federal prosecutor in the 1980s, I used to think nothing of scooping up the phone numbers that a suspect called. I viewed that surveillance as no big deal because the Supreme Court had ruled in Smith v. Maryland (1979) that we have no reasonable expectation of privacy in the phone numbers we dial, as opposed to the content of the calls. And in any event, I had limited time or practical ability to follow up on those numbers.

Today, by contrast, when I look at the government’s large-scale electronic surveillance of private communications, I see an urgent need to rethink the rationale — and legal limits — for such intrusion. The government now has the technology to collect, store, and analyze information about our communications cheaply and quickly. It can assemble a picture of everyone we call or email — essentially our entire personal and professional lives — with a few computer commands. In addition, given the pervasive presence of geo-locators on our smart phones, the government is able to electronically monitor and reconstruct virtually every place we visit — a capacity that will only increase with the growing practice of photographing our license plates and the rapid improvement of facial-recognition software in combination with proliferating video cameras.

The government claims this enhanced capacity to monitor our metadata has helped to foil terrorist plots. But officials have been hard-pressed to identify cases in which broad, unfocused electronic surveillance has made a decisive difference. Meanwhile, US law has not kept up with the dramatic new intrusions on our privacy made possible by current technology. [Continue reading…]