If you no longer want to monitor a feed for a particular site you can delete it from My Sites.

To delete a feed:

1. Sign in to Site Explorer to go to My Sites.
2. Click the Manage button next to the site URL you want to delete. The Manage Sites page opens.
3. Click the check box to select the Feed URL you want to delete.
4. Click the Delete button.

Note: Deleting a feed from My Sites in Site Explorer removes that feed from the list of sites you are monitoring. However, it does not remove the feed from the Yahoo! Search index.

For information about removing your URL from the Yahoo! index see: How can I delete my URLs from the Yahoo! index?