They did well to spot/stop them going into the stadium, especially at an away game.
These are obviously mindless idiots who deserve to be banned, but it does bring to light how social media is used/reviewed by clubs, as by the sounds of it, it was in a bar, so not in/around the stadium.
So what happens if a group of fans sing an offensive songs about the bitters or Utd, that may not be racist/homophobic, but just mean and nasty, could Liverpool ban those fans? not condoning their behaviour, just raising the question on what is deemed acceptable/not acceptable and who judges that, it opens up a big area, especially when it's not in the stadium and they are reviewing peoples posts.
I worked at a company about 5 years ago that was taken over by a bigger rival, a few staff posted on Facebook (on their own pages) how they didn't like this company and how bad it was, they were dragged into an office and forced to resign or be sacked., so this stuff can have a huge impact on peoples lives.
As for Salah, I think this will motivate him to show them how good he is, especially as he is an ex Chelsea player, don't they remember this? lol