Anabolics? Lol wtf, sometimes I wonder if you guys use your mind at all.
They contain taurine, which is a substance that causes some issues only if you suffer from epilepsy and you have a high am0unt of taurine / kg of your body.
What's dangerous in those drinks is the additives for the colour and taste and the preservatives. They also contain some am0unts of certain vitamins, so you should not consume too much in one day (max recommended is 2 monster per day).
Rockstar and monster also contain coffeine , which is known for carcinogenesis, and can blow you up if you drink too much.
Generally, up to 2 monster per day is not dangerous. After the 2 , they get a bit too much for your system, it's like drinking too much coffee or a bucketload of soft drinks.
But if you drink more than 2 monster (etc) per day, you must really waste money, cause that shit is expensive (they cost 2.30E each here in crete and ~the same at the shops I visit in Athens)