You never know who is looking. "Oh, there's a subaru like that one we stole, let me just copy that plate down and go and use it in some ram raiding/terrorism/general law breaking".
im not against the editing out plates thing, better to be safe than sorry, but on the subject, if some1 was wanting a reg plate to copy, they dont really need to look at pics on a forum to get it, they could easily get one simply by walking down a street or in a public carpark, etc
fuzzy