They sure do, and that is why forum administration needs to be quick on the ban button when one is detected. I used to work as an administrator on an ex-jokehovian forum that was trashed by trolls (before I worked trying to save it). About 90% of the "members" joining were spambots, often having porn that may or may not be legitimate porn on their signature page. I myself have had the pleasure of preventing them from joining that forum. (Other trolls were already there, and I saw about 15 of them being banned just before being promoted to administration).
And this is why IP bans are required. It isn't enough to do a simple account ban, since kikes can and will simply open another account and pick up where they left off. True, individuals can and do make trouble--hence using time outs and short bans when they break rules. Often, such rules include use of swear words, flaming, posting "spam", posting porn, and the like. Most ban "hate speech". Some have rules against multiple posting (posting more than once consecutively). Others have rules requiring proper grammar and spelling, or posting in English only. The forum I helped administer (ultimately, the trolls fucked it up beyond salvation) had basic civility rules against death threats, flaming, and the like but not against regular swearing (though I have had the privilege of helping deleting the same post across 15 sections). Others have daily posting limits, so you only post a few threads, to limit this.
Generally, if forum administrators are on the watch for this, and start issuing PermaBans for this (IP bans, not account bans), they would have to stop. PISSrael would waste their money, the paid trolls would be IP banned on most forums, and forums would be more peaceful. MySpace forums would have done well to institute a freedom of dissent policy where anyone spamming the kike version of issues would be banned permanently. Kikebook is even worse. And, if they know their money is wasted, they will have to start their own forums which would only wither and die because people wouldn't take them seriously.