The current list of servers toot.cat does not federate with:
rainbowdash.net, shitposter.club, freezepeach.xyz, social.headsca.la, woofer.alfter.us, social.au2pb.net, gorf.club, sealion.club, gs.smuglo.li, unsafe.space
Users of these instances are not necessarily "bad", but the types of content they allow run counter to this instance's CoC. If you feel like I missed any, or added one by mistake please let me know.