Football referees have almost an impossible job.
Supporters of football clubs are extremely passionate and, when a wrong decision goes against them, there is huge backlash.
The introduction of VAR has helped slightly but it is far from perfect and football fans still rage about refereeing decisions on a weekly basis.
So, what are the worst refereeing decisions in football history?
Goal asked football fans to name the worst decision made by a referee that they have ever seen.
Thousands of supporters commented and we've included some of the answers below.
Thierry Henry's handball | France vs Ireland | 2009
Ireland and France were in extra-time, with a place at the 2010 World Cup on the line for the victor.
Les Bleus took the lead late on in controversial fashion. Henry deliberately hand balled in the box and then set up William Gallas to score.
The goal was not ruled out and France held on to confirm their place in South Africa. Ireland, understandably, were livid.
Nani red card | Manchester United vs Real Madrid | 2013
Manchester United were leading 2-1 on aggregate against Real Madrid in the last-16 of the Champions League in 2013.
But, in the 56th minute, Nani was controversially sent off.
The Portuguese winger only had eyes for the ball when his foot made contact with Alvaro Arbeloa's ribs.
He was sent off and United could not hold on as they lost 3-2 on aggregate.
Robin van Persie red card | Barcelona vs Arsenal | 2011
Arsenal were leading Barcelona 3-2 on aggregate in their Champions League last-16 tie in 2011.
Van Persie was set through on goal in the 55th minute only for the whistle to blow for offside.
The Dutchman did not hear and, moment after the whistle blew, he had a shot on goal.
Van Persie was then given a second yellow card for time-wasting. Arsenal would concede twice more on the night to exit the competition.
Kieran Gibbs red card | Chelsea vs Arsenal | 2013
Alex Oxlade-Chamberlain used his hand to deflect the ball away from goal during a Premier League match between Chelsea and Arsenal in 2013.
What happened next was bizarre. Andre Marrinerr mistook Oxlade-Chamberlain for Gibbs and sent off the full-back instead.
Oxlade-Chamberlain admitted his guilt to Marrinerr but he did not change his decision.
Frank Lampard's no goal | England vs Germany | 2010
England thought they had equalised against Germany in the World Cup when Lampard's exquisite volley hit the crossbar and was evidently over the line.
But the referee decided it had not done so and play carried on.
Germany went on to smash England 4-1, but it could have been very different had Lampard's goal had stood.
Arturo Vidal red card | Bayern vs Real Madrid | 2017
Bayern were reduced to 10 men late on in their Champions League quarter-final game against Real Madrid in 2017.
Vidal appeared to win the ball in a challenge with Marco Asensio, only to receive his second yellow card.
Real Madrid went on to score three goals in extra-time to progress to the final four.
Raheem Sterling penalty | Manchester City vs Shakhtar | 2018
Sterling kicked the floor in the penalty area with absolutely no one near him.
The referee thought he had been touched though and gave a penalty.
Stephen Hunt's 'ghost goal' | Reading vs Watford | 2008
Stuart Attwell gave Reading a goal... despite the ball going nowhere near it.
You really need to see it to believe it.
Roy Carroll gets away with blunder | Tottenham vs Man United | 2005
Time was running out when Pedro Mendes tried an audacious effort from the half-way line.
It was going straight into Carroll's hands, but he inexplicably threw the ball backwards towards goal.
Carroll managed to claw it away, but only after it went a good metre over the line.
However, the referee decided that it was not a goal and Carroll got away with a huge blunder.
Jan Vertonghen's no goal | Tottenham vs Sunderland | 2015
Another call that didn't go Tottenham's way.
With Sunderland needing a goal, Tottenham broke and ended up scoring through Vertonghen.
The referee ruled the goal out for offside, though, despite the Belgian being in his own half and 10 yards onside.
It did not matter too much though as Spurs were still able to hold on for all three points.
Tom Henning Ovrebo's performance | Chelsea vs Barcelona | 2009
Ovrebo made numerous bad calls in this match.
Chelsea thought they should have had four penalties in their Champions League semi-final match against Barcelona, but none were given.
Andres Iniesta then struck late on to condemn Chelsea to a painful exit.
That sparked Didier Drogba's famous reaction at half-time...
All these errors were shocking.
One refereeing mistake that, unbelievably, no one mentioned in the comments was Diego Maradona's 'hand of God' against England in 1986.
That's arguably the biggest refereeing mistake of all time.
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