The company I work for have a small Plone blog. But we have a problem with spam accounts. We use captcha on the site and Plone sends a mail to the users that they must confirm before they can edit the user profile. Still about 600 spam users are created every day. In the Plone user profile they paste all kinds of commercial links.
We are located in Denmark and the blog is in danish, therefore I have made a script to delete all users with a non danish mail adress. But even though most of the real users have a danish mail account I probably still deletes some real users when running the script.
The spam users register from a vide range of ip-adresses, so blocking ip's is not an option.
Does anyone have ideas to what to do about this problem?