If Matthew Inman wrote anything with the specific intention of goading anonymous Internet users into committing torts or crimes against Carreon, then Inman could have real problems.
I don't believe at all that that's Inman's intent.
Everything The Oatmeal wrote is still available[1][2][3], and I didn't see any suggestions that users attack or otherwise harass Carreon or FunnyJunk. In fact, the owner of Funny Junk sent a direct message to all users of the site asking them to "contact" Inman "any way [they could]".
I don't believe at all that that's Inman's intent.