AddThis

Looks like you've enabled address bar tracking which appends those parameters to your URL. They're there so that we can collect analytics when someone copies the URL out of the address bar instead of going through our sharing tool. It shouldn't affect people linking to your site and can provide insight into what content is the most popular on your site.

If they're not wanted or are causing issues, you're free to disable address bark sharing tracking. Just adjust your addthis_config variable like this:

<script type="text/javascript">
var addthis_config = addthis_config||{};
addthis_config.data_track_addressbar = false;
</script>

More information about address bar sharing analytics is available here: http://www.addthis.com/help/address-bar-sharing-analytics