Blacklist

A Blacklist collects known sources of spam. Email traffic then can be filtered against a blacklist to remove spam. If an Internet service provider provides this service to a spammer and does not take action after a warning by the blacklist's administrators, all email traffic -- also by legitimate users -- from this provider is blocked. This usually creates anger among the provider's non-offending users, which will force the service provider to take action against the spammer.

lists that either search engines or vigilante users compile of search engine spammers, which may be used to ban those spammers from search engines or to boycott them.