I think this incident is quite a simple one to resolve really. Ban the fan for life (or at least 10 years) for being a twat and entering the field of play as its not allowed and other fans have had the same fate.
How anyone can say its ok cause he was having the craic is deranged. They are saying that it is acceptable to run on the pitch and dance like a dick or whatever, hey we might as well sit by the touch line if its all ok. Or is there gonna be a time limit for entering the field of play? You have to have rules otherwise fans may attack players, has happened.
Its harsh to fine Celtic football club but we were fined for a similar incident and tons of other clubs have been as well. Its the failure to control the fans bit you see.
Dunno about banning them, that'd be harsh for one dick head running on the pitch.
Seen the incident now and that Dida needs a word, what a total cock. He needs banning for a few games for being a nancy, if only that.