facehole
A facehole is someone who can't resist adding a snarky remark to every post they see on Facebook, like they're paid to be a pain in the ass.
You post a photo of your dog, and they comment, 'That dog looks like it’s been hit by a truck.'
Your friend shares a birthday wish, and they reply, 'Happy birthday, loser.'
You update your status to 'I’m tired,' and they write, 'No kidding.'