I think it all depends on the country and where the plane is going. I've had to take off my tevas (sandles with no place to hide anything!) and I wasn't wearing socks even!

Airports also have the air-puffer machine now. Have you had the experience??
You stand in a small booth and air is puffed down over your body.
They say it's to detect certain powders (explosives, I guess).
Another fun experience!

Have you gotten poofed?