They may've signed up for the service to stay free of unsolicited email, but people in <A HREF="http://news.zdnet.com/2100-1009_22-6068392.html?tag=zdnn.alert">Blue Security's "Do Not Intrude Registry" are getting spammed,</A> the company said Wednesday. What's more, a spammer is attempting to intimidate the Blue Security customers by sending them threatening messages, according to the Israeli company, which launched its spam-fighting service in July last year.