Roy Keane cut a terrifying figure in his playing days for Manchester United, but that was nothing compared to the wrath he unleashes these days when asked by fans to pose for a selfie.
One unlucky punter found out the hard way at an NFL game between the Green Day Packers and New York Giants that was played in London.
The Giants shocked the Packers 27-22 for their best start to an NFL season in 13 years and Keane was an enthralled spectator in the stands.
That was until the brave fan interrupted the experience to try and grab a quick selfie with the football legend.
Keane was visibly annoyed at the request and repeatedly said 'after the game' while trying to crane his head around the nuisance spectator blocking his view.
After the punter continued on their way down the aisle, Keane rolled his eyes and shook his head.
In truth, this punter got off lightly. Keane is so well-known for his dislike of selfies there is an entire Twitter account dedicated to it.
The account features images of a cranky-looking Keane pestered by fans while eating ice cream, waiting at the airport and even while trying to pick up the evening supper from the local chicken shop.
Some fans said it was poor form of Keane to brush the supporters that made him rich and famous.
'Disgraceful. Of course he's going to be in the public eye it's part and parcel of the job. More than happy to take the big bucks when it suited,' one fan posted
'Don't blame him, he was trying to watch the game and not get pestered all the way through it,' said another
'He's right too, the game is on. It's like your missus asking you to change the babies nappy. Get a grip,' was another perspective.
'There's a time and place for that celebrities rarely get any privacy when they step out of their homes,' said another.
'Anyone would be annoyed with a selfie during the game, he could've been a bit calmer, but it's Roy Keane after all,' added yet another.
But many were quick to rush to Keane's defence as well.
'The man has publicly stated he's never liked being asked for selfies. He's just keeping the same energy, I can respect that,' one fan said on Twitter.
'All he is saying is 'after the game'. Anybody who has bumped into RK knows it's his automatic response,' reasoned another.
'Good for him, he's not public property. Anyone asking for a selfie are just sad individuals, unless they're kids,' tweeted another.
'You have to draw the line Roy, if you don't they'll be knocking on the door whilst you're taking a dump,' added another.