Like some of you guys, I kind of skipped over alot of the terminals so I only had 15 hacked at end game. After searching for a while, I finally found an exploit. This will allow you to hack the same terminal again and again. First, YOU MUST HAVE THE CASTLE unlocked. Second, go to S. Boston Military Checkpoint. This is important: DO NOT KILL ANY GUNNERS AS IT WILL BREAK THE GLITCH. There is an expert terminal near a Power Armor Frame, and once it is hacked DO NOT OPEN THE DOOR and travel back to the Castle. Rinse and repeat. Here is a video for those that want a visual guide: