I didn't miss that point at all actually. Twitter isn't the main medium book thieves use. It's just one they're trying, and seemingly abandoning judging by the way those mentions have tailed off - it clearly doesn't work for them for obvious reasons. It's a lot easier for them to be picked up through simple Google searches on the files those tweets refer to. Plenty of people are finding their stolen books the obvious way - a simple search. Try that and you'll see people having conversations about the books they're nicking.