The vest thefts have not deprived any troops of them, As of last month, the U.S. Army had 163,000 Interceptor Protective Vests. The marines say they have enough of these vests for their troops as well.
Soldiers and marines have been caught stealing Interceptor Protective Vests and selling them to civilians, including criminals. These vests are the "flak jackets" with the ceramic plates that stop high powered rifle bullets. Government investigators have so far discovered sales (for $200-1,000 each) of 539 vests and 506 ceramic (bulletproof) inserts. Police have recovered 88 vests and 104 inserts and identified 157 suspected sellers. However, only seven suspected sellers have been hit with criminal charges so far. The vests were often stolen by soldiers or marines who had access to them where they were stored before being issued to troops. Sales were showing up on Internet auction sites like eBay. Normally, these vests are only sold to police or the military. If criminals get them, this could endanger the lives of police down the line.
Theft of weapons and equipment by troops has long been a problem, although a minor one. In some countries (like Russia) it is a major problem. The United States has extensive inventory control procedures that hold up most of the time. Every time a new commander takes over in units down to the company (100-300 troops) level, an inventory is held and both the outgoing and incoming officer sign off on it. But the rush to get through all the paperwork often results in false entries in order to cover up "honest mistakes." The same ancient and traditional methods (saying material was lost accidentally or destroyed in use, for example) are sometimes used as a cover for outright theft. There is another layer of inspections which inventory the normal inventory efforts, plus criminal investigators who are always on the lookout for the small number of thieves they know are out there. That's how the flak jacket thieves were caught.