What security against this do you have in place?
Use Q and A if you do not already have it enabled:
- ACP - Settings - Options - Human verification Options
then
- ACP - Settings - Human Verification Manager
I'd not recommend reCaptcha as there are well known (by spammers) ways to get through it.
You can also use promotion:
- New members only have write access to one forum, hidden from others
- If they behave, then you can promote them to a group with full rights
Admins / moderators can monitor the hidden forum and ban spammers before they do any harm. The promotion can be done automatically.
But first, what have you already done?
|