matrix.rocks has blocked the following instances:

blob.cat for "cat pic"
01001010.net for "CF"
01001010.social for "CF"
01010011.xyz for "CF"
014450.xyz for "CF"
01bit.xyz for "CF"
030.me for "CF"
04.si for "CF"
0702.org for "CF"
0ab.uk for "CF"
0badc0.de for "CF"
0ch.tv for "CF"
0chan.ru for "CF"
0day.agency for "CF"
0daysto.live for "CF"
0ko.me for "CF"
0n.ee for "CF"
0ne.day for "CF"
0pp.us for "CF"
(the list has been truncated to the first 20 entries)