Comment on someone's Facebook status / Delete your comments to make it look like they're talking to themselves
A Trollface meme.
Trollface is the iconic rage comic grin: a wide, mischievous smile drawn in MS Paint by Carlos Ramirez in 2008. It's the universal symbol of trolling - provoking people for laughs - and the face that says "problem?" Captions describe pranks, bait and harmless deceptions. It's one of the oldest and most recognizable images in internet culture.