Lots of praise for #Eintracht#Frankfurt's fan culture in recent weeks (rightly so), but also certain distinctions to be made within active German fan scenes, particularly between "ultras" & "hooligans," none more so than in Frankfurt...
Displays, fan marches, atmosphere etc are generally conducted by the ultras. The "Ultras Frankfurt" are one of the biggest such groups in Germany.
German ultra groups are generally fairly left-leaning and don't go actively seeking violence, although they will defend themselves.
German "hooligans" however will go looking for violence and will often organise arranged fights with like-minded rival groups. They're often increasingly professional, oganised, MMA-trained & (far) right-leaning. There may be the odd individual link to ultras in some cases.
Frankfurt's hooligans are notorious. It's likely (although not certain) they were behind attacks on West Ham fans, who will have been seen as legitimate targets due to a) historical reputation of Eng fans, b) tendency of Eng fans to act up abroad/"take over." It was predictable.
Unfortunately, many Ger hooligans don't seem to have clocked on that most travelling Eng football fans in 2022 are far from the "hooligans" of the 80s or who they've seen in films, often resulting in innocent fans getting attacked, which also may have been the case in #Frankfurt.
(To be clear: I'm absolutely not condoning violence around football matches, nor defending Eintracht Frankfurt's hooligans. But hooliganism is an aspect of German fan culture which exists, with its own nuances and complexities, so hopefully this provides some informed context.)
If you're interested in the topic and can read German, I highly recommend the work of @RobertClaus13 for all the information you need: robertclaus.de/?page_id=28
If your German's rusty, this may also help to understand some of the complexities of German "hooliganism" and ultra culture - albeit in the context of #Borussia#Dortmund in this particular case: