How to protect my site from spam members

Hi!

I notice a bunch of members started joining my site and I realize that most of them were spams. I don't know how it passed the captcha keys but I figured out its manually created account. Is there anyway to protect my site or ban any members for automatically joining my site and making blog post and among other things?

Thanks,

Sam

Turn off auto join via admin.

and let them confirm with Email link or let your site admins  activate joined members

Its all here.....

http://www.boonex.com/forums/topic/spam-spam-spam-spam-IDEA-.htm

 how to do that? Thanks!

check this

Mandatory Confirmation module on market