When the bots attack! [closed]

Answer 1

http://chongqed.org/ maintains blacklists of active spam sources and the URLs being advertised in the spams. I have found filtering posts for the latter to be very effective in forums.

Answer 2

For human moderators it surely helps to be able to easily find and delete all posts from some IP, or all posts from some user if the bot is smart enough to use a registered account. Likewise the option to easily block IP addresses or accounts for some time, without further administration, will lessen the administrative burden for human moderators.

Using cookies to make bots and human spammers believe that their post is actually visible (while only they themselves see it) prevents them (or trolls) from changing techniques. Let the spammers and trolls see the other spam and troll messages.

Answer 3

A popular method on forums is to simply queue the threads of members with less than 10 posts in a moderation queue. Of course, this doesn't help if you don't have moderators, or it's not a forum. A more general method is the calculation of hyperlink to text ratios. Often, spam posts contain a ton of hyperlinks, and you can catch a lot this way. In the same vein is comparing the content of consecutive posts. Simply do not allow consecutive posts that are extremely similar.

Of course, anyone with knowledge of the measures you take is going to be able to get around them. To be honest, there is little you can do if you are the target of a specific attack. Rather, you should focus on preventing more general, unskilled attacks.

Answer 4

You can use Recaptcha to at least make a captcha useful. Then you can make questions with simple verbal math problems or similar. Microsoft's Asirra makes you find pics of cats and dogs. Requiring a valid email address to activate an account stops spammers when they wouldn't get enough benefit from the service, but might deter normal users as well.

Answer 5

Block access based on a blacklist of spammers IP addresses.

Answer 6

I know some people mentioned ASIRRA, but if you go to all the adopt me links for the images, it will say on that linked page if its a cat or dog. So it should be relatively easy for a bot to just go to all the adoptme links. So its just a matter of time for that project.