There's a private group on Facebook called J1 Chicago 2018 and the concept behind it is pretty self-explanatory.
Students who are currently out in Chicago on summer visas are added to the group and can talk about things like where to go and what big nights out are coming up in the area.
On Tuesday night, however, a bizarre post was put up by one member of the group who said that over the weekend, himself and "three friends were refused entry to this 'Irish Bar' because we are Irish.
"If this involved any other ethnic group it would not be tolerated. Discrimination of the highest order."
Shortly after the post, floods of comments came in which said that the same thing was happening several Irish groups who tried to gain entry into the bar.
"Same thing happened our group, an absolute disgrace!!!"
"We were told a group of Irish lads had been there earlier that day smashing glasses whilst topless and that the Irish weren't being accepted again there this summer.
Halligan's is an Irish bar in Lincoln Ave, Chicago.