Didn't see anything, but i'm sure it was just exaggregated and very biased thing.
Not that polish fans are saint, like their great pope, but as always, there are two sides to a coin. Only this coin has the darker side a bit bigger. Nothing beats angry bunch of, turks or serbians. That's where the proper hell lies imo.
If they managed to get stadiums ready, the organisation will hopefully keep it safe, hooligans will most likely won't get in anyway, because half of the tickets goes to sponsors. Nobody wants international shame live in TV. Only thing that could bother them is the possible debt.