radiosocial.org is a Mastodon instance for radio amateurs. It's a fairly new system in 2018, but already the local timeline is well dedicated to radio interests. It's run by Andy M1LOL (@ak).
Mastodon is a worldwide federated network of systems which run a social network. The user interface is reminiscent of Twitter, but the experience also has some element of Usenet News in that your account is tied to a particular server with an admin who has responsibilities both for system administration and some measure of local leadership.
I have long thought that I might be interested in finding such an online home for radio, and I'm encouraged by what I see so far. There are other ham networks out there, but it's always nice to get in on the start of something.