@lanodan @crafti @Jain @Moon It sounds like they aren't very transparent about the process or giving other instances a chance to respond before or after blocking.

I'm not really familiar with what they do, I do think it is okay for them drop instances based on their own rules and whim. Or just to federate with a few instances. The main problem comes when they try to do more than this.

I was trying to think about what the OP could do. I've never felt the need to have a blocklist. I think that word of mouth between admins is the best method when problems do happen and each admin can decide what is best for their instance.