You should use captcha.

You must enable the captcha plugin to stop the automated form filling .

That's it! the captcha is enable... I was thinking in something that could be able to identify a invalid e-mail or name, you know?

Hello Rubens, Amit,

The captcha should stop bots from registering. Some bots are better than others in beating this system, but it is clear that you will keep out some bots.

Unfortunately, from what I am seeing the majority of spam operations are using manual labor of a modernistic kind. I think Charlie Chaplin would have loved it. People sit behind pc's and are busy grinding out blogs, registering, filling in the captcha etc.

I had some similar looking e-mail adresses appearing with unvalidated users, but it seems Google blocked their e-mails or they suddenly had something else to do.

You could look at Stopforumspam.com for some help.

Regards.
Gerrit Venema

Humm, I undertand... thank's Gerrit! At this moment what i can do is delete manually this user when he register, but, right now, i have 38 motherf@#$% that is doing this. I realy need to find a way to block this... and if I find I will publish here the solution for everybody!

Thank's everybody...

All the best

The stopforumspam's API is now wrapped to an elgg pluggin and you can download it from http://community.elgg.org/pg/plugins/project/656224/developer/webgalli/antispammer-for-elgg. When used along with the captcha /recaptcha plugin, its a good tool to reduce the spam register to 90% of the current hit on your site. Use that plugin and add them to a common DB.

Thank's TeamWebgalli. I'll try right now.