And now United fans have been warned to expect the Glazer family to respond stubbornly to their recent protests over their ownership of the club.
Supporters have since written to co-chairman Joel Glazer to warn of continued lawful protests if steps are not taken to give them a louder voice and a greater say in how the club are run.
But Dr Dan Plumley of the Sheffield Business School at Sheffield Hallam University believes American owners have a history of being thick-skinned, and have been prepared to upset entire states in the past.
“One thing we know from history with American involvement in football clubs – and we’ve seen it at Arsenal – they do stand their ground, they are pretty stubborn,” he told the PA news agency.
“That is rooted in the way their sports are run. (Arsenal owner) Stan Kroenke picked up the Rams (NFL team) and moved them (from St Louis to Los Angeles) and nobody can tell you you can’t.
“You upset a full state by moving it, but if you’re prepared to do that then you can do it – you’re the owner. That’s just not the English model and that’s been the cause of the friction over the last few weeks.”
Forbes Magazine valued Man Utd at $4.2billion (just over £3billion) last month, making it an asset within the reach of only the super-rich.
Plumley added: “There’s a potential for this sort of protest to cause damage to the valuation of the club. The angle is to hurt the Glazers in the pocket, but it won’t do too much, to be brutally honest.”