Issuing a subpoena is a more direct way for police to try to get the social data of people they have their eye on, but law enforcement departments are often trying to obtain social data from protesters in one way or another. Officers ask Facebook to tap into messages sent on the social network as well as messages sent on WhatsApp, which Facebook owns. They have also used social media monitoring services such as Geofeedia, Media Sonar, Digital Stakeout and others to track the social accounts of protesters in real time.
Facebook, less and less attractive as a social channel. What's the next great social outpost?