I only show my face in my private gallery. I'm considering taking those down because, quite honestly, I get far more calls than people I can see and it's just not worth the worry.
I've made peace with the idea that I may be found out. My boyfriend and his family know. My mum kind of knows (she assumes a sugar daddy type scenario). I'd rather people in some of my social circles didn't or potential employers, so for me it's probably not worth it.
If you're not struggling to get work, I'd not bother with face pics. Most clients who see me comment that they most enjoyed the effort I'd put into my profile, blog and website. None have been disappointed with my face!