Certain things are too horrible to auction on the Web.
Consider that eBay recently halted auctions on:

Human Remains
Human Parts
Humans
Microsoft Products

Pretty soon they're gonna ban sales on pentagrams and demon-summoning
paraphenalia.

Is there anywhere on the web where it's still safe to sell Evil Things?

-- From a Slashdot.org post in response to eBay voiding auctions
of legitimate second-hand Microsoft products