Mastodon is a free, open-source social network. A decentralized alternative to commercial platforms, it avoids the risks of a single company monopolizing your communication. Pick a server that you trust — whichever you choose, you can interact with everyone else. Anyone can run their own Mastodon instance and participate in the social network seamlessly.
Instances that engage in illegal activities or system abuse (such as DDoS, spam, etc).
These nodes have communities that are disruptive, abusive or otherwise unwanted behavior. This does not include "free speech zones" but specifically monocultures where node administrators or the community as a whole engages in harmful behavior. You are free to engage with these communities though it is requested that you consider not reblogging on public timelines.