Trolling

[DAnvilFan]

This is trolling, at least to some degree. The "herring" poster is fishing for a response from other parties and the moderators in order to shut down a particular mode of discussion with a malicious (or at least poor-mannered) intent.

Right, I've noticed this one too. In some forums I've visited, this is monitored pretty sternly and threads with such posts simply have the posts removed instead of the thread getting locked.

But I've seen way too many long discussions where eventually somebody threw in, as you say, a red herring. The discussion proceeds as before until suddenly you see a post with "om nom nom nom nom" followed by some random picture of a kitten with some stupid subtitles such as "epic fail kitten is epic," followed by something equally dumb, until a few posts later you see that the thread got locked.

Meanwhile, said discussion is never properly finished and the OP still doesn't have his questions/concerns answered.