They should all receive LIFETIME bans. Getting caught up in something stupid on the field during play is one thing but coming on to the pitch and then chasing someone around trying to basically give them a good kicking is beyond the pale!!
The thing is, this has been going on in south American football for as long as I can remember and on odd occasions it is much, much worse but the authorities there just don't seem to care. Either that or they are too scared of the "fans" to do anything.
Probably too scared of someone putting a horses head in their beds.... Maybe it's part of the "charm" for the fans seeing a good fight. Sometimes you forget how "civilised" our game is in comparison
I used to listen to Tim Vickery a lot when I was night taxiing, he often warned visitors to be careful if watching any football because of the big influence of gang culture at most grounds in Brazil!
I have seen TV programmes that suggest that is so very true, more so in Argentina but I guess they are pretty similar over there.