If you want to get really technical, I researched it a long time ago.. So i am not going to dig up all the legalities for you..
It doesn't matter WHO took the photo, if it contains a picture of a person in it they are the copyright holder unless a release form is signed.
Most of the pics you see are from people standing in crowds that took them or what not.
The others that are taken specifically for a magazine most likely have those release forms.
I have only heard of a few celebrities going after people to shut down sites that were derogitory to them using those pictures, but not many at all..
1.) Yes they are most likely violating some copyright somewhere.
2.) No, no one gives a crap.
Its kind of just like speeding, its a law its there, not many people follow it or abide by it, and 99% of people get away with it.
Morally, ethically and from a business standpoint its wrong.
The cost for these people to protect these copyrights costs more than its worth to defend..