There are a lot of comments here, but I don't see anybody asking one particularly important question (and please forgive my ignorance of Riseup.net). Why did removing one server cause so much disruption? Do they not have back-ups? Redundant servers? If this stuff is so gosh-darn important, I feel these users have put their faith in the wrong hosting organization...
riseup is a collective driven isp that is focused in social change activists, so they do have values and principles different than making money. the issue here is not the disrupt, it's the attack on those values.
i hope you now understand why nobody ask about that, it is important, but not the issue about this. also it's because this values people put faith in them and not in google, amazon or another money focused company, me included :)