Camping overnight with a tent in the Dolomite mountain range

I was planning a trip to the Dolomites with my friend, and had an idea of sleeping overnight in a tent up in the mountains. I imagine the sunrise there would be an incredible view to see. I have a question about the legality of camping up there. I read in few places that its prohibited but I have seen some people do it. Do I am left wondering if this option would be legal and possible, does anyone know??