You have no idea what the supporter may be holding, a hidden knife or broken bottle for example.
If anyone is crazy enough to run onto the pitch and attack a player or ref they deserve the kicking they will get.
I will praise the keeper for defending himself against the muppet.

This is not like the Cantona incident as the keeper never left the playing area or entered the stands.

Personally I’d take red card (and the support of my team in walking off the pitch)

Good to see the keeper didn’t go AZ on him :-)

dammit they blocked the clip already! Saw it earlier on facebook though. Made the cantona incident look like a bit from the smurfs film

For me the goalkeeper was an animal and it is necessary to sanction it, there was no need to keep on stamping on it to the fan when it was already in the flat.

The pitch invader deserved a good kicking but as a player you just can’t do that sort of thing. I don’t think the ref had any option but to show red. Players have been sent off just for pulling down pitch invaders so what was kicking the guy on the ground twice going to get him?? it may not be right but thems the laws and the GK should have known that.
Interesting to see if the club is fined for pulling the team off.