Encrypted Anonymous Coward writes "The Baltimore Sun reveals the existence of an interesting experimental NSA program codenamed ThinThread from the late 90`s. The program involved link analysis of traffic data, with a twist; The phone numbers from the U.S. would only be analyzed in an encrypted form. This way the analysis would potentially be possible under existing privacy laws, according to the people behind the program. The NSA could gather further unencrypted details if there was evidence of a threat. Political infighting seems to have dropped an interesting and respectful program from the books."