A.D. had stolen the file (and Noel's) from an underground lair in Aunt Carol's house. A.D. used the file as blackmail in Power Play to get Aria to go against her friends. This file is known to get Ezra arrested because Aria accused him of Statutory Rape.
The file was given back to Aria as her prize in Driving Miss Crazy.
"I'm a student at Rosewood High School and I have had a sexual relationship with my former teacher Ezra Fitz since I was a sophomore. Until now, I have been too ashamed to come forward but now I have come to realise that Mr. Fitz is a twisted, conniving predator and I need to stop him from ever doing this to anyone else. He needs to charged with exploiting a teenager when in a position of power."