I don't say well done to them at all. they were things who took any opportunity to violently attack people. punching children in the face, a group of men kicking someone who was prone on the floor multiple times in the head.
they are thugs who should be arrested.
if you see someone going into a cinema or a concert without tickets then I'm sure you would immediately start wading in punching them left right and centre. why is it any different at a stadium?