Block lists in BlueSky are automatic moderations lists that other people can subscribe to.
We recommend always subscribing to the lists with the "Mute Accounts" option only, since there's no way to unblock unique users from a lists, it's either all or nothing. In case an account is wrongly blocked by accident, you would have to unblock everyone.
With the mute feature, you'll see a warning on people's profile letting you know they have been flagged by these lists, and you'll have the choice to decide what to do about it.
Accounts that are confirmed to be minors or that don't follow the rule of having an age indicator visible on their profile
Accounts that post hate speech of any kind or that use the community tags / spaces with the sole purpose of attacking the community at large or a particular artist, ship, dynamic.