Spammers getting through TOS and Activation Email

I am having spammers sign up and activate the blog. I have the terms of service set up and did not have this problem until the last few weeks. Now I get 5-15 new blogs to delete daily from this new threat.

They all have the same look, areallookingname4444444@different.com's.

lydia5778607 (lydia5778607@jobreviewsblog.info)

There have been a few that come from the same domain. I have not checked for repeated IP addresses.

So this new threat can fill in the right fields on the sign-up page, check the box for TOS and then click on the activate link in the email sent to them, is the way it looks.

Suggestions for defeating this?