Sci-hub has gone offline

It's up for me. Both sci-hub.ac (which I usually use) and sci-hub.cc.

Firefox says that the sci-hub.cc server is configured insecurely; but I have no problems when I use Opera.

It's just www.sci-hub.cc which gives a 403 error response: sci-hub.cc, sci-hub.ac and www.sci-hub.ac all work as usual in a brief test.