Auto-generated contents or more precisely 'spam' that targets comments sections or forum threads on most websites, not only disrupt those visiting a site, but also results in displaying contents that as a webmaster you may not want to be associated with your site or to Google and other search engines.
In a guide published today, Google's Webmaster team walkthrough to deal with this type of spam in your site and forum. The motive of these spammers posting deceiving content and links on a site(s) is either to take down their rivals (believe me this is true), or is an attempt to get more traffic to sites ownened by them.
In the picture below, you can see a few examples of such auto-generated keywords:
The team Google recommends following ways to secure your site's forums and comment threads clean as well as making them unattractive to spammers:
Keep your forum or bloggs, bulleting boards, and any other content management system software updated and patched.
- Use a CAPTCHA service like reCAPTCHA, Securimage and Jcaptcha, for users to confirm that they are not robots, or an automated script.
- Block suspicious behavior by setting up time limits between posts, and look for excessive traffic from individual IP addresses or proxies and other activity more common to bots than human beings.
- Review recently joined users on your forum who has excessive amount of posts to make sure their posts and threads are not spammy.
- Consider to disabling some very old forum threads or blog posts from comments.
- Enable moderation and reputation features for users to post before links, and also disallow anonymous posting, make new users require approval before their posts are publicly visible.
- Consider blacklisting obviously spammy terms. Built-in features or plugins can delete or mark comments as spam for you.
- Use the "nofollow" attribute for links in the comment field to deter spammers from targeting your site.
- Use automated systems like Akismet to defend your site.