High Quality Content by WIKIPEDIA articles! The Blue Frog tool, produced by Blue Security Inc., operated in 2006 as part of a community-based anti-spam system which tried to persuade spammers to remove community members` addresses from their mailing lists by automating the complaint process for each user as spam is received. Blue Security maintained these addresses in a hashed form in a Do Not Intrude Registry, and spammers could use free tools to clean their lists.