I have no sympathy for right-wing extremists, but EU countries still operate within the rule of law. You cannot deport people who are member of a legal organization, and I don't think there is enough evidence to declare it a terrorist organization.
I feel making a case that they are either a terrorist or just a criminal organisation would be the easiest way to get rid of them outside of turkey. Such cases are really subjective so it shouldn't be that difficult. Just last month a greek far right political party was judged to be a criminal organisation. Grey wolves could share their fate.
There are a lot of ideas here sparking with (at least) border-line racism (against racist, but it's racism nevertheless).
But what you say stands out, because there is an easy solution that's not tainted by racism: These people are threatening other people. They form an organization to promote this. We as a society have a tool against that: Law.
We certainly have law, but they are not applied. It is hard to pick people from the mob an put them on the stand. And these people hide in a large groups. Same as Nazis did. Alone they are afraid and harmless. We seem to forget the history here. If we don't suppress extremism early we will have much bigger problems.
