An arrangement for arresting a portable object, such as a desk computer, to a stationary object using a cable (40), one end of which is looped around the stationary object. The other end of the cable (40) is secured to a block-like cable-shoe body (44). An oblong circular cavity (46) is formed in the body (44) with an undercut portion (48) extending along about 180 degrees of one side thereof. Further provided is a lock member (10) having a ribbed attachment portion (24). The attachment portion (24) comprises a recess (26) defined between first and second ribs (28; 30) and is adapted to be inserted into the cavity (46) and shifted into engagement with the undercut portion (48), and then locked thereinside by push-in key operated device (50). Said lock member (10), with ribbed attachment portion (24) is affixed to a side wall of the portable object in various conventional manners.