Originally Posted by Reinz
...No danger with airsoft.
Not exactly. They can sting, and getting hit the eye could do damage. Wear eye protection.
That said, the good ones the look and function like the real thing can be very useful training tools. Some instructors use them for Force-on-Force training (with appropriate safety gear). We use them with our beginner students before we take them on to the range for live fire exercises.
They are also fun.