Of course, it's impossible to stop anonymous individuals from the Internet from fucking with someone once they're riled up, and I'm pretty sure everyone involved in this knows that. Indeed, The Oatmeal appears to be relying on this as a tactic.
The Oatmeal appears to be relying on this as a tactic
I'm not sure why you feel this is the case. They've been careful to redact Carreon's contact info from the document's they've published and they've been saying things like "And to anyone else who is reading this: it goes without saying, but stop harassing Carreon. Be lawful and civil in your interactions with him."
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]".