On one hand I can see how these things would be tools for trolls, especially editing posts in a locked thread, however, deletion of one's own thread is something I would consider less so. If someone is a troll, I doubt that they'd post anything important like our Assorted Helpful Links thread in the first place. Someone would have to be very motivated to contribute a useful thread for an extended time and delete it out of spite, and that's not exactly trolling. It's still an issue, if it were to come up, but I can't see that being a thing that happens very often.