I take lots of photos (guessing most of you know that by now :-) and seldom concern myself about a license plate. I find faces to be much more of a grey area, what with the facial recognition software that's commonplace (flickr, picasa, you name it).

In both cases I apply a simple bit of common sense: 
1. if it's a stranger and not in a crowd (or campout) I'll ask permission in a casual way if I can
2. if I intend to do anything "formal" with it, including selling it or using it for promotional material, I get clear and explicit permission

As for risk, on a scale of 1 (low) to 10 (high) I'd put it below 1.

Regards, Peter Kraiker
nextchapter.kraikerphoto.com
Toronto, ON, Canada
'82 L Westfalia 1.9 TD 5 Spd (Babe)

On 2012-07-27, at 11:52 AM, Roland <syncronicity1@GMAIL.COM> wrote:

> Is this really a risk?  Can somebody use this info in a bad way?  Is it a
> security or privacy issue really?  And how would somebody use this info or
> do something with it?  I really cannot think of how some bad guy would do
> something with the info.  I guess if someone worked at the DMV they could
> look up my address (and get arrested), but so what, you can do that in
> other ways.