if its still the same abuser
This is why many of the blacklists are all screwed up. There is no standards and people are are put into 2 classes, abusers, and non-abusers. If you ask 100 people to define abuser you get 100 different answers. If you ask a blacklist operator to define the term they will either ignore you or scoff at you. Then they will give a childish argument that networks are private property and they can block what they want that disregards the actual issues that operators normally have contracts with their users and labeling people as "abusers" with no real definition can lead to legal liabilities. Of course anyone who brings up these issues is labeled a spammer which is why these issues never get corrected and why most blacklists are not legitimately operated. A blacklist operator should have standards for putting people on the list, as well as an appeal and review process.