For one thing, security is no longer just a blue collar job. It has become a white collar profession requiring college-educated specialists. You can't depend on the retiree-age security guard at the front door. Most successful thefts are done by highly professional teams that do a lot of scouting, planning and surveillance.
Consider the case of the largest pharmaceutical theft in recent years. On a stormy Friday night, March 14, 2010, thieves scaled up the side of Eli Lily's Enfield, Conn., warehouse, cut a hole in the roof, rappelled down into the warehouse, and disabled the alarm system. For the next three and half hours, they filled a 53-foot trailer with about $76m of drugs (Prozac, Stattera, Cymbalta, Zyprexa, Gemzar, Alimta, and Efient). This same gang had already done heists at Bayer, GSK, and J&J, but those were all in the $3m to $10m range.
