Comments, in the form of a letter to the U.S. Atomic Energy Commission, on the AEC proposal to restrict access to "extremely sensitive" technical and scientific data developed independently of the government. The AEC bases its proposal on the premise that gas centrifuge technology offers great potential for clandestine operation of small enrichment plants and therefore poses a serious challenge to the effectiveness of nuclear safeguards. It is the author's view that the proposed rules are a potential danger to the freedom of scientists and engineers who are not associated with the government to communicate their findings to others. By sharply narrowing access to privately developed information in certain technical areas judged sensitive by the Commission, the rules would make it more difficult to evaluate or oppose government decisions. 14 pp.