Vlemmy.net was my first home instance. The admin was responsive, transparent, and, most importantly for me, had a fairly absolutist perspective on free speech, refusing to defederate with anything at all, preferring to leave the choice up to the user. Unfortunately for him and the users, the Irish government, where Vlemmy.net was hosted, has a less favorable view of certain communities that it inevitably federated with.
Because federation causes copies of content to be saved to each federated instance, he wound up finding out that certain communities hosted content that, once saved onto HIS server, would get him sentenced to the Irish equivalent of "Federal Pound-Me-In-The-Ass Prison". He defederated those instances, but the next day, Vlemmy.net was all but gone. His payment sites for donations now all lead to closed accounts, and I have not heard anything about anyone getting in contact with him.
The common understanding is that he got spooked by the potential legal ramifications, and either got a visit from the Irish authorities or was afraid of that possibility, and so chose to pre-emptively pull the plug. This all occured roughly two weeks ago.