Tsu Surf was arrested earlier this month on Federal RICO changes that consist of murder, drug dealing, and robbery.
While we don't know the specific details of the murder part, the indictment against Surf says that he was selling drugs -- pills and marijuana -- on Instagram.
US Marshalls subscribed to the battle rapper's social media channels, watched him and listened to him, and documented everything.
The Feds also used his social media to locate him when it was time to swoop in and make an arrest.
The indictment goes back to 2015, meaning the Feds have a whole lot of info on Surf and all those he dealt with.
The 32-year-old is currently in Essex County Jail in Newark, N.J.