Mark writes:

Usenet itself began to die out in large numbers with the advent of
Facebook.

Usenet has been on the decline for years, ever since alternative discussion
venues have become available, most of which do not require a special
interface. I haven't seen any acceleration in the decline because of Facebook,
though. Facebook itself may turn out to be a flash in the pan.

Moderated groups on Usenet have always been very quiet compared to unmoderated
groups. There's plenty of censorship elsewhere on the Net. An attraction of
Usenet is that it's still a bastion of free speech (relatively speaking).