Many people are quick to say that certain exercises, like the behind-the-neck press, will cause injuries. Of course, anything can cause injuries, especially if you're doing anything worthwhile or rewarding. The trick is to make your body physically prepared to cope with the demands of training.
With the behind-the-neck overhead press, the risk simply comes down to your posture. Bad posture? It's not the best choice for you yet.
You may know the name of a particular exercise, but do you know what the agonists in the movement are? How about the synergists? Hrrummpph! And you call yourself a weightlifter!