Sounds like a revenue opportunity for a savvy web developer who is less lazy than I am and will actually bother to do the implementation. Set up a web service that makes a note of all your user names on all the various social networking sites, so people can check whether a particular site profile actually belongs to you. If there is a profile on a site but you haven't registered it yourself, a quick will reveal that you aren't the owner. There isn't any need for the new service to have any connection with the social sites, but I guess it could have for added value. Needs a way of proving who you say you are to stop the jokers from grabbing your name on the new service, but cleverer people can work out those details themselves.