Police tactics, ground changes, putting responsibility more on to the clubs, and a good degree of managing the groups of supporters. Companies would once finish early if there was a Wednesday match and their office was even vaguely on a route to the ground. By the nineties and noughties, normality was far more expected.
Far more has been for security theatre and red top media campaigns that the "government must DO something!!!!". So government does do something. Like rings of steel around London. Tanks at airports (huh?) and all the rest. Despite this a man in a van can still perform a terrorist outrage on a bridge, or take a bomb to a teen pop concert.
We're far more likely to hear some days after that some perpetrator was known to police or security services, than all the security theatre prevented some atrocity, or the perpetrator was arrested en route.
I'm not old enough to remember football hooliganism in the 80s and before, but abroad at least, it was very far from solved by the 90s - which is why passports are taken away.
> than all the security theatre prevented some atrocity
Without commenting on how effective any of this is, you won't hear about prevention because it isn't news.
By the nineties there was just a dwindling hard core minority of hooligans, that were starting to become removed from the clubs. Same for the international element, it had become some thugs being thugs, and mostly separated from grounds, matches and the general support. They tagged along with the footie event, for a good punch up in a city bar or city square. From a point of view of "everyone well behaved" it remained a problem. From a point of view of hundreds or thousands of opposing supporters kicking off, it was mostly solved.
Prevention isn't news, but arresting someone preparing a bomb, or caught on a bus with a machete on their way to wherever is. Yet for all the additional surveillance...
See also, The Troubles
Really that's the core liberal/conservative policing distinction: the conservative argument is that some people are really bad and that justifies measures taken against them, and the liberal argument is that actions of the police should be judged as acceptable or unacceptable regardless of who those actions are against.
Protest has also changed from the anti-"G8" anti-globalisation days.
> anti-brexit, anti-austerity and anti-trump protests
All those things appear to still be happening despite the protests. I should have said "effective".
What protests are ever "effective"? They're a warning to those in power more than anything else. Usually the repercussions for politicians are felt years afterwards, for example Labour losing elections and Tony Blair being unable to participate effectively in UK politics any more.
Also regarding the protests - it really depends on your definition of effective. I don't think anyone thought they were going to topple the Trump presidency by protesting when he visited. They were just expressing that they believed he was not welcome here. And given the media coverage and the comments from the man himself I'd say they were quite effective.
If this was a good justification for this kind of measure (abuse) can you imagine what Germany should do given their history? Yet they'd rather go for less divisive solutions.
What if there are better ways to prevent repeating the mistakes of the past that don't involve making even bigger mistakes? But those ways give more power to all people instead of just some people so I can understand why mass surveillance was the go to instead.
> those measures were considered necessary and a re supported by a large part of the public
All slippery slopes start somewhere high and this is all people are shown at first. But it's the bottom you should worry about instead.