Thanks for your input! It is always valued.
Over the past month, I've been working hard at exactly this, and have successfully removed over one thousand spam bots. I use several types of searches to comb the user database for matches, and then manually delete the entries that are so clearly bots.
Unfortunately, due to the advanced nature of the newer generations of bots, creating a fix-all solution simply is not possible at this point. A captcha-based user verification has been implemented in the past, with limited success. Bots could read it anyways in some cases, and others would create their own form to submit for registration, bypassing it altogether. A validation email was also used in combination with this for an extended period of time, but we can not depend upon the spam-blocks employed by some of the cheaper mail services to let our mail through.
We have bans on all email addresses that end in the typical spammer junk, including .biz and .info domains. We also use an
external database to supply our ban tables with IPs and email addresses that need to be banned, with varying degrees of success.
Fortunately, nearly 90% of the bots that manage to get registered here on RolePlayGateway fail to post due to the more complicated posting system we use, but this is not the case for some of our other enterprises, such as the
Grand Tournament. In all situations, it is important that we work as a team to fight these spammers. From moderators deleting posts to site administrators manually grepping the database, this is a coordinated war that requires all the help we can get.