Examples of airline security lapses
At the bottom of the page.
Also: NBC investigative piece 5 years ago found outrageous lapses in security.
Failure to do background checks.
Cheating allowed on security tests
Unrestricted access by unauthorized personnel.
Zero training
All of this designed to reduce the cost of personnel by dumbing the job down to minimum wage level.
security
Like Phil says the onboard security is somewhat cut and dried. Airport security is much more difficult and the cost will be astronomical if the problem is left to the bureaucracy.