I went to use the facilities at a Target once. Go in and come to the first stall and give a little tug on the handle and it’s locked. Not wanting to use the potty right next to whoever was in there, I went to potty #3 and opened the door.
To my shock and his, there’s a college aged dude sitting there on the pot with his pants and undies at his ankles, his phone is out covering his goods, thankfully. I immediately said “Dude!!! Lock the door!!!” and slammed the door and decided to hold it till I got home. I heard the guy apologizing on my way out.
I always look under the doors now but greatly appreciate anyone that would also give me courtesy cough!!