To protect the integrity of our systems, we do not provide information on the sources of any invalid clicks. Doing so would provide assistance to those who would attempt to find and exploit potential weaknesses in our Click Protection System.

When it comes to using our blocked domains feature, you can often determine which sites or pages may not be performing the way you want based on your business goals by reviewing the data from your web server logs, account reports and other account data.

For more info on how to read your web server logs and on tracking URLs, visit our Help Center at http://help.yahoo.com/l/us/yahoo/ysm/sps/start/overview_trackurl.html.