That's from digital cameras that can't deal with low light conditions. I doubt PS introduced those, but PS might well show them. I see this in PS 5.5 as well but I don't see this in other image viewers. They're still there though. They can be changed one pixel at a time with the eyedropper and brush tool. The quality of the camera at low light has all the world to do with this. Now I'd be surprised to hear if these were flatbed scanned photos. Shouldn't happen with that.