Abstract: This invention is directed to protection against theft or other unauthorized removal of articles secured by threaded nuts or the like, particularly truck tires. A tamper-proof fastener is provided having a locking cap which engages the underlying lug bolt and a seal which surrounds the locking cap and the lug nut of the tire to be secured. The seal rotates freely about the locking cap and the lug nut so as to prevent anyone from loosening the lug nut without first breaking the seal.