Oh yeah, it's quite a fortress.
Two years ago the police wouldn't let AJAX fans watch the game in rotterdam because of vandalism in the trains. As a result, we stranded on 100 metres from the stadium. Whole the game we had to sit nearby the stadium listening to our radio's while the cockroaches (nickname of feyenoord-fans) were targeting us with stones; the two sides only separated by a fence.
Although we only saw the game on the telly afterwards, I vividly remember that day, being 2-1 down in stoppage time and 2-3 up at the end of the game... But on the other hand, that was (probably one of) the reason(s) that the cockroaches went insane, first throwing rocks at us and later challenging the ME (MP)...
Last year, they beat us both at home and away, but due to a new system, the play-offs, we've played them again, winning 3-0 and 2-4. After the 2-4, about 800 cochroaches were waiting at us at the bridge nearby the station where we had to take the train back to Amsterdam. To avoid riots, the police arrested all of them, so that we could have a safe journey home...(is part of a new law to prevent football-riots)
What I'm trying to say, I think, is that the police and the authorities are prepared for riots and that's why it's very likely that only minor incidents occur...
Still, I don't put on my AJAX shirt