mastodon.science.social has blocked the following instances:

076.ne.jp for "hate-associated"
1611.social for "anti-lgbtq, hate-associated, hate-speech"
5dollah.click for "anti-lgbtq, harassment, hate-associated, hate-speech, racism"
activitypub-troll.cf for "dos, harassment, spam"
adachi.party for "harassment, hate-associated, hate-speech, racism"
aethy.com for "inappropriate, underage"
annihilation.social for "harassment, hate-associated, hate-speech"
asbestos.cafe for "alt-right, anti-lgbtq, hate-associated, hate-speech, racism, underage"
bae.st for "alt-right, anti-lgbtq, hate-associated, hate-speech, inappropriate, nazism, racism"
banepo.st for "antivax, harassment, hate-associated"
baraag.net for "hate-associated, inappropriate, underage"
beefyboys.win for "hate-associated, hate-speech"
berserker.town for "alt-right, anti-lgbtq, fascism, hate-speech"
bird.makeup for "bots, twitter"
blob.cat for "harassment, porn"
boymoder.biz for "harassment, hate-associated, hate-speech, racism, underage"
breastmilk.club for "anti-lgbtq, harassment, hate-associated, hate-speech, racism"
brighteon.social for "conspiracy"
bungle.online for "hate-associated, racism"
(the list has been truncated to the first 20 entries)