I know that Google Webmasters have a tool to de-credit links that might come from a bad site etc.
Can you let me know if:
1. It is worth doing and it works (i.e. the De-Authorize tool)
2. Is there a way to check whether the site that has given me the link is 'bad'
NB The link that I am referring to comes from someone in a forum that links to me in a positive way but the site is from a hacking community that doen't look too bad, I guess I just want to remain vigilant on these things.....