I have one on my PC but not on my Mac. I use it next to never. No point in it really.
ONCE, just once, I cammed with somebody and when I came I found my semen was full of blood due to a prostate injury. There was blood everywhere. It completely freaked out the guy at the other end and I was not only panicked but intensely embarrassed. It's a pity because he was a nice guy I would have liked to get to know better.