Ahh, the magic conditional word "can". It basically means that there is a chance of something happening, no matter how slight of a chance there is that it will happen. Clapping my hands while I'm walking along a busy street "can" cause somebody to crash their car, if they happen to turn their head to look at where the clapping sound is coming from, and by doing so, fail to notice that the car in front of them has stopped. The chances of this happening is very slim, but there is still a chance that it could happen.
I always thought it depended on the definition of "is". Now I find out it all depends on the definition of "can".