Google has finally released a tool in Google Webmasters that will allow website owners to disallow bad links their website. There have been many concerns of competitors and users spamming links to drive down another competitors website keyword ranking. This tool should help stop unnatural link building and tedious work of asking a webmaster to unlink a bad link. To find these bad links you can use Google Webmaster export links to your website or use a 3rd party tool to scan all links to your website.
For complete information on the Disavow Links Tool visit Google’s blog spot:

A new tool to disavow links

Tuesday, October 16, 2012 at 1:43 PM

Webmaster level: Advanced
Today we’re introducing a tool that enables you to disavow links to your site. If you’ve been notified of a manual spam action based on “unnatural links” pointing to your site, this tool can help you address the issue. If you haven’t gotten this notification, this tool generally isn’t something you need to worry about.

Author

Yang John