ZitatWhat is donotlink? Linking to dubious websites
You've all heard there's no such thing as bad publicity. On the internet this is doubly true. When you link to a website — regardless of the reason — this strengthens its position in search engines. This means that a bad review of a website makes it more popular.
When you are discussing or alerting others to a website that promotes a fraud, scam, cult or other questionable business and you link to that site, search engines will (after a while) improve the offending site's rank. Therefore, more people will find these shady websites, and will be exposed to their content without getting the proper context. That's where donotlink comes in.
With donotlink.com, you can link to sites without giving them "Google juice".
Donotlink uses three different ways to block search engines from crawling a link. So you can post the link on forums, message boards, facebook, twitter, reddit, and other public places without giving shady websites any undue credibility. http://www.donotlink.com/dnl/faq