Many British people were upset at what they saw. And I have some sympathy: mob rule is generally a bad thing, and risks getting disastrously out of hand. But what a glorious moment. It’s an image that will last years in the memory, as the moment that people in one English city said the ritual humiliation of black lives was no longer acceptable. You can say “Black Lives Matter” a million times but it will change nothing. This action changed things.