Not for the first time, an English crowd has been far from impressed with the refereeing display of Turkish referee Cüneyt Çakir.
Having angered Manchester United fans with the controversial sending off of Nani in a 2013 Champions League clash against Real Madrid, Arsenal supporters were frustrated by some of the decisions made by Çakir in their first half against Barcelona.
Having given the visiting team a few questionable free-kicks, the home crowd were quick to criticise the referee.
https://twitter.com/ReadArsenalFC/status/702225257206308866
And criticism of the referee wasn't limited to Arsenal supporters in the stands.
https://twitter.com/Gaitxn/status/702225217792376832
https://twitter.com/BrittanyYoungx/status/702228749652197376
https://twitter.com/ClassyCoutinho/status/702228728504459265
https://twitter.com/DanielJBothwell/status/702228724180238336
https://twitter.com/KyleDRFC7/status/702229454685388801