A Jewish friend who was recently working briefly in Bulgaria went to a game there and was genuinely shaken by what he saw there - not just hooliganism but incredibly widespread racism, with swastikas commonplace. I'd say that qualifies as worse than the England idiots, if one's compiling a league table, which is a bit tasteless in itself.
What's going on at the Euros resembles, from a distance, a strange attempt at a Fear the Walking Dead homage. It's frustrating that little analysis has come through so far as to why it's happening. The usual socio-economic factors, sure, but the organised nature of much of the violence, seemingly co-ordinated between as well as within several different countries, is the surprise. Tournaments can easily present such phenomena as sudden and isolated when in reality they've been developing for months or even years, but I've not noticed it except, I guess, in the former Eastern Bloc. And it's there that UEFA has had the chance, and good reason, to act, going back years, and its failure to do so, in spite of scandalous incidents there at all levels of football, could well be seen as a contributing factor to what's happening now.