You get your instance included in "tier 0" block-lists by having 1 large Mastodon instance arbitrarily add your instance to a published block-list which then gets blindly copied by multiple other large Mastodon instances, and thereby this cabal of Mastodon instances forms an "algorithmic" "consensus" that your instance is dangerous/harmful/XYZ because it's included on multiple block-lists and therefore must be problematic (otherwise, why would it be on so many block-lists?) ​​