Unexplained website users

I have been getting many unexplained sign-ups as users on my website. They are not signing up for my programs. Just, I believe, via the WordPress default sign up process. Many of them have email addresses ending in .pl. Attached is a screen shot of the most recent entries: Can anyone help me figure out why and how this is happening?

Looks like it is probably spammers. Here’s a link to a similar issue: http://wordpress.org/support/topic/weird-user-registrations-with-pl-emails Looks like as long as you set registered users to very limited permissions, you should be fine.

Thanks. Very helpful.

Apparently bots have cracked many captcha images. Changing my forum to a math question at sign up dropped the spammers (primarily bots) 100%.

Do you notice that there is an increase in the number of spam comments? Did you turn on Askimet as well as captcha for register? I think you should step up the security to reduce the number of spam users.

How do I set CAPTIA on the WordPress sign-up page?

Perhaps this link can help. It’s WordPress plugin; different but compatible with Akismet:

Thanks