The Riddler, or Enigma as he is known in this game, has hidden 200 datapacks around the city, with each one containing blackmail data. As you collect them, you will eventually piece together the extortion files that will give you details on his plans. Each file is composed of 10 datapacks, so when you find the ten needed for that file, you will complete it.
The locations for the datapacks only appear on your map after you interrogate his henchmen, who appear after paying a visit to Enigma's headquarters early in the game.
