That is most likely being added by the AddThis code, because you have requested to track URL’s when they get copied and pasted, rather than just when someone clicks on a button.
If your code, you probably have something like this:
<script type="text/javascript">var addthis_config = {"data_track_addressbar":true};</script>
change {"data_track_addressbar":true} to {"data_track_addressbar":false} will turn that off, but you will lose the ability to track that kind of sharing.
Mod
