You hire a contractor to build a system and provide them requirements. But you forget to ask the contractors to make it secure.
So who do you blame when your website gets hacked? Well, the contractors of course.
“Navy Hacking Tied to Contract,” Wall Street Journal, March 7, 2014 A6 http://on.wsj.com/1ggguJi
Okay, it was an old system. But no one was responsible for updating security. Or someone figured the risk was acceptable. Oops.