not only it is not deleted, people with no facebook accounts already have them. each time you visit a site with like button you are being tracked (see fb patent

not only it is not deleted, people with no facebook accounts already have them. each time you visit a site with like button you are being tracked (see fb patent to track users with social buttons). information from that tracking is being saved into a "virtual" fb account, and if you ever make an account, the virtual one and your new one are being merged