The TSA is like someone who only locks one car door

One more reason to believe that securing airport terminals from explosives is like putting up a fence around 1% of your yard:

CNN | Pauline Chiou | Acid attacks are 'easy' in Hong Kong

Hong Kong, China (CNN) -- Another mysterious acid attack took place during the weekend in Hong Kong. It was the sixth such incident in the past year.

The target is always a crowded street full of shoppers and the weapon of choice: plastic bottles filled with acid.

There will always be concentrations of people outside of security cordons, and those people will always be vulnerable to bombs, bullets, fires, corrosive chemicals, electrical currents, falling objects, mean people with pointy things, fast moving chunks of tubers, and all manner of other stuff. It's silly to rope off a tiny portion of our public space and attempt to secure it.

Preemptive investigation and rapid emergency response, people. That's all that will protect us.