Search for sites that use Google AdSense IdSameOwner.com allows to search for sites that use given Google Adsense ID. Google Adsense ID looks like pub-2695993077060885. Sometimes people steal content of webpages entirely, without removal of Google AdSense ID from the pages. So by searching for sites with Google Adsense ID you use on your sites, you'll be able to find all sites that have stolen content of your pages.
To search for sites that use Google Adsene ID, just enter it into the main entry field, without quotes, so the entry contains just something like pub-2695993077060885 (without quotes) and hit Enter.
Please note: you earn money when somebody clicks on the pages with text stolen from you, so you may wish not to stop thieves using your Google Adsene IDs :-)
SameOwner.com knows about 1546 thousands sites containing Google AdSense Id, so happy searching!