social.targaryen.house ("House Targaryen", "STH"; home) is a Mastodon instance operated by user Wonderfall, who appears to be based in France. It was created on 2017-04-01 As of 2017-06-19, it had 3,817 users, making it one of the larger instances.
STH became notorious in June 2017 for Wonderfall's "neutral" stance toward the abusive behavior of some of STH's users, which has had the result of nurturing free speech trolling.
Unfortunately, the transient and sometimes private nature of Mastodon can make it difficult to document what was said when and by whom; if an account is deleted or hidden, it is very unlikely to have been archived anywhere -- so it is often necessary to rely on 3rd-party reactions and accounts.
As a result of this policy, STH was blocked by a number of other instances including:
- anticapitalist.party 
- kitty.town 
- mastodon.social (home; the "flagship" instance with 81,215 users as of 2017-06-19; admin is Eugen (Gargron), the primary author of the Mastodon software)
- ...and then unblocked as of 2017-06-19 
Wonderfall's statements about neutrality include the following, all on 2017-06-14:
Even if I disagree with his political ideas or whatever, I prefer to stay neutral. My instance is not a "safespace", I rather see it like a "neutralspace".
Some of his posts are ambiguous, but I have nothing 100% explicit. In that case, users have all the necessary tools to silence undesired content.
What neutral is for me : as an admin you consider the first line of defense resides in the tools users have at their disposal. If the situation becomes more serious, eventually the admin can intervene.
This is certainly a bad look for tons of people, but not for me. I'm obsessed with this : the less I do, the better, since I don't want to influence others.
But my post has to be seen in this context : I'll always respect law, if there's something really bad, the first line of defense will be me for sure.
Another user, Zuse, showed up in the same thread with some classic freeze peach:
But you do realize that advocating cencorship and restricting freedom of speech is just as bad - if not worse?
Ironically enough: those are in fact nazi methods.
I don't share the opinions of that user - just like wonderfall does not. But not liking one's opinions is no reason to exclude them. Unless ofc. they violate (inter-)national law.
There is advocation of restriction of fos here. That's what started this thread in the first place. It is the other way around: Ethics (in theory) dictate law. And the point is not to "give nazis a platform" but tolerate that people have right-wing opinions in a neutral space, just like tolerating left-wing and all other kind of opinions.
After some further discussion, Wonderfall then asked for specific examples of harassment, which he was given. User H5N10 was blocked or removed at an unknown time between 2017-06-14 and 2017-06-19, and their posts are no longer accessible.
- 2017-06-14 exchange with Ginny McQueen @ kitty.town other end, with Wonderfall's responses blocked
- 2017-06-15 Anticapitalist Party statement about social.targaryen.house
- others have blocked targaryen, including some major players
- 2017-06-19 Ginny reports that mastodon.social has unblocked STH; follow 2nd link for links to anti-Jewish slurs -- but account has been removed, so can't verify or quote
- ↑ House Targaryen: about/more
- ↑ 2017-06-15: Anticapitalist Party statement about social.targaryen.house
- ↑ anticapitalist.party: about/more (two archive attempts on 2017-06-19 and one on 06-20 failed; archive available offline) STH was not listed as blocked on 2017-06-19, but was listed on 2017-06-20 for "uncompatible Code of Conduct".
- ↑ blocklist, 2017-06-19 archive
- ↑ Ginny McQueen, 2017-06-18 (3rd party; looking for primary source)