It's a harassment vector that has even been the topic of a lot of controversy in Mastodon already. Some instances got harassed for their public instance block l

It's a harassment vector that has even been the topic of a lot of controversy in Mastodon already. Some instances got harassed for their public instance block lists. It wasn't even personal blocks, but instance-wide and instance-to-instance blocks (and then in-fighting). A lot of instances like the transparency of public instance blocks, especially as that can be a helpful tool for evaluating an instance's admin policies from the outside if you are looking for an instance to join. However, the same helpful tool also gives trolls ammunition when they are looking for "fun" fights to pick and suggests who might be "weak" to their attack.