>When viewed from the GMail web interface they look totally legitimate, you can only discover the real sender by looking at the mail headers (and it's not even easy to show them in GMail anymore).

I had never tried to view headers in the Gmail web interface before, and it took me literally 5 seconds to figure out how to do it (down arrow next to the reply button, click "Show original"). Sure, it's not the most obvious feature on the screen, but that seems reasonable given that most people have no idea how to interpret that information anyway.

So the spammers can just delete all of the "crap" by deleting posts made by the same IP address right?

>The obvious move was to just fill up their database with crap data, so I hacked together this little bash script and handed it out to a few friends..

Sounds like it will be more than one IP address, but you're right it's probably not many.