I got in before they started asking for the crazy stuff. I'm not really sure what information I would be willing to give. I'd probably give a LinkedIn page to the more reputable orgs. I think they are trustworthy enough not to let it get out. Of course, all you would need to do is give a LI page of someone that looks similar to you and then go by that name. If that's not enough, then I'd move on.
A C-org, however, I would give NOTHING...other than describing who I am so they know that I match the description when I show up.