I want to prevent bots from register in my forum. How can I make it so that the person that register have to solve for example 2+2 before he can register ? I have IPB.
what forum script are you using? a few opensource forum scripts have image validation/captcha scripts that can be just plugged in..
have a look at this: http://mods.invisionize.com/db/index.php/f/7430 it's not an image verification but it requires an extra step of setting the value in a dropdown... this can work as a temp. solution until you get an image verification/CAPTCHA system implemented in your forum.
nice happy it worked... but like i said in my post.. this should only be a temporary fix.. remeber these spammers are constantly improving their bots..and it wont be hard to add another field where the dropdown is set to the correct value. you should keep on looking for a captcha image plugin available for your forum software and install it... or if your budget permits it hire a coder to do the job.
A method that works quite well on the directory I'm helping manage is to check the IP address via PHP or whatever and reject their registration if you can't get the IP. This stops a lot of spamming programs
Anyone using phpBB, can just turn on either, user or admin authentication, in their admin configuration settings, that stops all the spamming programs I have ever come across.