good idea, this should be a chrome extension that shows you what its found on every user you interact with. maybe a badge to show how many networks its found them on, and an interface to view what those networks are, instead of an extension that modifies the DOM
I remember a while ago a similar tool was posted but that one could also derivate similar accounts if any of the originally found accounts had an email exposed or something.
Does anybody know which one I'm talking about? My Google-fu is failing me