Just played with a Rioter who used the ? ping in unintended ways
He even pinged ? when I was doing wraiths to heal up to full, then when I teleport to the enemy's bare ass nexus and backdoor it somehow for some strange reason the ? pings stopped.
I'll be honest. I'm fine if my friends do it, but if I don't know you, then it's pretty toxic to deal with. Especially when I get a large amount of them in a short time.
So is Riot going to change the name of the ping from "Enemies missing" to "passive-aggressive way of telling you I didn't like that play"?