There are some CBer's who know who they are, and are willing to share. I know (well, I know who one is), but will go to my grave with this information. There is a group of very important Disers on the duct tape patrol willing to stop any and all blabbers who wish to tell who they are (I believe Dream is there commander and cheif). I am not a part of this elite, well-trained commando troupe (although I wish I was), but I support them with all my silence.
Sometimes you can ask to be tagged, and it happens. Sometimes they just pick up something cute that you say, and the next thing you know, it's in your tag.