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.
If you're an athlete or a gym rat, how much should you be able to deadlift? Two times your bodyweight? Three times? Or is the better question should you even be deadlifting at all?