On Monday, a rogue spammer sent threatening e-mails to a number of members of Blue Security\u2019s "Do Not Intrude Registry," a group of roughly 450,000 members dedicated to battling the proliferation of spam, meant to intimidate them and undermine the group\u2019s efforts, according to\u00a0a May 1 press release.Blue Security is an anti-spam firm formed in 2004 to develop methods of eliminating spam and junk mail.A number of the e-mails received by Blue Security members claimed that any person who continued to use Blue Security\u2019s Blue Frog software, which enables them to automatically opt out of spam lists, would face retribution.Eran Reshef, Blue Security\u2019s founder and chief executive, said the threats only serve as proof that the group is effectively intimidating the spammers. \u201cThis is just proof that the Blue Community is an effective deterrent to spammers that are using unethical and illegal tactics to promote their products and services,\u201d Reshef said. \u201cThis incident is only a futile attempt by a degenerate spammer to fight back through intimidation and extortion.\u201dReshef noted that the Do Not Intrude Registry is encrypted and that all member e-mails are protected from potential spammers. He also said that since the spammers already have the targeted members\u2019 e-mails addresses, they aren\u2019t at risk of \u201cexposure.\u201dAccording to Reshef, the Blue Security Community has already persuaded the parties that generate a quarter of the world\u2019s spam and half of the all the illegal junk mail to become compliant with the Registry, or to at least initiate compliance efforts.For related news coverage, read Sophos: U.S. Still Generates the Most Spam and New VoIP Phishing Scheme ID\u2019d, Blocked by Cloudmark.Check out our CIO News Alerts and Tech Informer pages for more updated news coverage.