Being a linesman requires a great deal of concentration, as you must simultaneously watch the ball being played while watching the line.
It's not an easy gig, and it's certainly not a smart idea to use your phone while running the line. Yet that's exactly what the assistant referee did in the recent Bulgarian tie between Chernomorets and Cherno.
The man with the flag casually chats away on his phone, before turning his head away from the action for several seconds to hang up the call and presumably update his Facebook status or something.
One would suspect this kind of footage would land a linesman in hot water, but neither team actually complained about the officiating and this particular linesman is Georgi Tabakov, son of Bulgarian regional football association head honcho Emil Tabakov. So there's a good chance he'll escape punishment.
According to The Guardian, former player and current Bulgarian official Tihomir Bobolov said "This is not on, whoever his father is."
If Bobolov has a problem, perhaps he should just call Georgi Tabakov to talk about it during his next match.