Util., 160 N.E. 321, 322 (Mass. 1928) (having a driver???s license is ???a privilege??? that is ???neither a contract nor property, and its revocation deprived the petitioner of no vested right???); Luk v. Commonwealth, 658 N.E. 2d 664, 669-70 (Mass. 1995) (???one???s right to operate a motor vehicle is a privilege voluntarily granted.???).