How about instead of scammer names put a list of trustworthy people? I sold like tons of loompoints and no issues so far
People who want to buy heirloom points simply need to spend 2 minutes doing a bit of background history on the seller tbh, it's pretty simple.
If you search my name in marketplace for example, you will see a whole page of lovely, clean, locked (unlike poophammer) threads. You can read said persons posts, to see who they are, if they are in a well known clan etc etc...it's all there, you just gotta look. Like Meow said, you don't just hand over your car keys to some guy selling flyers at your front door.