It's a difficult one.

Online, requiring photo verification when signing up for an account would help insomuch that action can be taken against that person if required. However, you would probably also get a push back from people not wanting to hand over their details to these big corporations.

On the terraces, the only way to deal with the immediate problem is to be tougher with punishments. Permanent bans and massive fines as well as a conviction would certainly help.

In society in general, I have no solution. There needs to be better education from a young age but people are filled with hate from various sources so it's difficult to combat.