"They just shrug... They don't think that someone is jamming their conversations." A friend of mine bought a cell-phone jammer two months ago and has been happily creating "sanity zones" within which cell phones are rendered inoperable. People have a right to communicate, he conceded. But "I have the right not to participate in that communication process - I really don't need to hear people yelling into a cell phone if I'm standing half a block away." (And excellent comments at Metafilter)