Where to report spam violation (link techniques to fool search engines)?

If you spot unethical spam techniques on website (whether it is your competitor or not), you can report to search engines directly using the following email address/website:Search Engine Contact:ask.com reportviolations@askjeeves.comOpen directory staff@dmoz.orgGoogle www.google.com/contact/spamreport.htmlMSN support.msn.com/feedbacksearch.aspxYahoo! add.yahoo.com/fast/help/us/ysearch/