Automatic account creator on my page | Fake Accounts and advertised topic

[ExXeL]

Hello,

Someone on my page are registering accounts names with fake e-mails like ConorMad | conormad.imbd1.ru
Who is create this accounts on my page is advertising in topic.
I want to know how can i build a security for this action
Sorry for my bad English. I hope you can understand.

[drewactual]

cleantalk is a paid for service but one that has been great for my use.  they have an SMF mod.  i've noticed no lag while using their services.

insofar as actions you can take, set up a series of security challenge questions- they can be found in the registration area of your admin panel.  simple questions that only users of your site- people who are interested in your subject- will know right off, but others won't.   this seems to be the best defense from being infiltrated by spammers.