Emufarmers Sangly wrote:
As near as I can tell, these bots (I would call them
vandalbots) are simply
out to maliciously damage wikis, much as crackers sift through sites running
old versions of phpBB and deface them. There doesn't have to be a profit
motive
Never attribute to greed that which can be explained by psychopathy.
Or, if you don't mind
sacrificing a bit of accessibility, you can just set the CAPTCHA to trigger
on unregistered users' edits and registration attempts.
I've had good luck doing this with reCaptcha. It eliminated (so far)
all user-creation bots and valdalbots.
Mike