I could never put my picture on here. If it was required, I'd be gone!
It depends on what industry you work in. It seems like no matter what you do, and what you try to hide, there's always a chance you'll be found out by someone. If you work with children, in government, or various other professions, it wouldn't be in your best interest to post a face pic here. And once you start posting face pics they are seen all around the world, can very easily be copied and used as the home page for any porn site, dating site, or who knows what site.
If you own your own business and have no one to answer to but yourself, that's fine. The only problem that could ensue is if someone saw you on here and word got around. Some people would be cool with it, and others might not be so forgiving which could affect your income. Putting your face on the net is definitely something you should not take lightly.
Stacy, even though your body and face pics are separate, your face could wind up anywhere and there's no denying it's you, unlike a body shot with no face.