I suppose there are exceptions, but crowds generally seem like a bad thing. Perhaps there is something to be said for transcending egoism by merging with a mass of people, but losing yourself is usually losing yourself in something, and what this is matters (it seems to me). So waving a lighter while singing along with thousands of other people to "Free Bird" or "Sunday Bloody Sunday" can't be good, even though those aren't bad songs. If you're going to give up yourself it should be for something better than that. This has something to do with integrity or honesty. Roughly: you should sing your own songs.
The idea of a non-conformist crowd is absurd. So this story about political slogans at a football match seems to miss the point. Fans holding up banners that read "The Truth Is Always Revolutionary" and "There Are No Idols" are not being political so much as absurd. Art doesn't make football political. It makes politics absurd. This in itself could be political, puncturing overinflated myths perhaps, but obscure, arty slogans are quite different from the more common, thuggish politics associated with, say, Lazio (nicknamed Nazio by some because of their fondness for fascist salutes and banners).
So I like the 'philosophical' banners as a kind of joke, but I don't expect them to change the world.