Looking under the stall door in a public restroom to see if it's in use. Checkacrapulation prevents the awkward pushing on a stall door or the even worse embarrassment of opening the door on someone sitting on the pot.
"I just barged in on this old man taking a dump."
Anything that is truly repulsive or that is seemingly harmless but, nonetheless, grosses you out.
"Did you see those two people making out over there?"
"That sickens me."
when you're riding along in the car and you see that the people in the car next to you are staring at you; also you could take action as an autopeeper.
I was autopeeping that chick and I think she just picked her nose!