All the time! It doesn't just happen to me, I count on it to happen and have even deliberately announced that I was going to the bathroom to try and trick it. XD
This 1 time i went to the kitchen to get dinner and i came back and there was a key on the screen i ran at the computer with the food in my hand i tripped on my dog and everything went flying.....then i realised my friend had posted a fake key i was very upset. btw plzd to meet u ashleys bro :D