Update. Now I'm receiving nasty emails from this filepile crew. Apparently I had the audacity to mention their secret sandbox in public and it made them cry.
Updated update. Now filepilers are emailing to apologize on behalf of their community, and to explain the confusion, and to attempt to taunt me. It's quite bizarre. From one of the emails:
Some other members are trying to figure out who sent you the nasty e-mails, but I wanted to apologize on the community's behalf. Most of us are pretty nice people, I swear, but like any online community, there are a few jerks out there.We don't like our own members to mention File Pile?! Oy.
We're fairly secretive -- it's one of our quirks -- but harmless. (Your commenter "Stewart" was in error: we're not an offshoot of SA, and forging UA strings isn't what we do.) We don't like our own members to mention File Pile, and evidently someone overreacted bigtime.
Again, my apologies for any distress that our more thoughtless members may have caused you.
I quoted the apology and nice parts of this email to be fair to the person who sent it. He asked me not to quote from or publish his email. Too bad.