Search for sites that use Google Analytics IdSameOwner.com allows to search for sites that use given Google Analytics ID. Google Analytics ID looks like UA-184918-2. Sometimes people steal content of webpages entirely, without removal of Google Analytics ID from the pages. So by searching for sites with Google Analytics 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 Analytics ID, just enter it into the main entry field, without quotes, so the entry contains just something similar to UA-184918-2 or UA-184918 and hit Enter.
SameOwner.com knows about 3074 thousands sites containing Google Analytics Id, so happy searching!