Wondering Why You Have So Many Subscribers in Your Users Area?

If you don’t have registration disabled, robots can find the registration page that WordPress automatically generates and register a bunch of bogus emails. Find this in your dashboard under Settings > General

Test out this link for your site
http://yoursite.com/wp-login.php?registration

If you do want people to be able to register on your site, be sure to use a good plugin like Anti-spam or Captcha by BestWebSoft (not all captchas are created the same)