Big Brother is watching you, listening to you, and tracking your every interaction.
Stingrays work by tricking cell phones into contacting them as if they were cell towers. This makes it easy for law enforcement to snag metadata, such as numbers dialed and how long conversations were, as well as the location of the phone itself. Stingrays do this indiscriminately to phones in an area, such as an apartment block. They also disrupt phone service for large numbers of people. US Marshals have even taken Stingrays (or devices that achieve a similar effect) to the air, which involves still more indiscriminate data being sucked up. (The CIA played a role in setting that one up.) Privacy advocates at the Electronic Frontier Foundation (EFF) call Stingray-style searches general warrants for the digital age, meaning they are at their core unconstitutional.