Maybe calling them Keystone Kops is giving them too much credit after all.

A Ban on Carry-On Luggage - New York Times:

In a directive whose logic is not always apparent, the Transportation Security Administration has spelled out what airline passengers can carry on board with them, what must be placed in checked luggage, and what can’t go on the plane at all. Knives must be checked but knitting needles and corkscrews are allowed in the cabin. Up to four ounces of eye drops can be carried aboard, with fingers crossed that multiple terrorists won’t combine their allotments to exceed the limit. Laptops, digital cameras, mobile phones and other electronic devices are permitted, so never mind any warnings you’ve heard that they could be used to trigger a bomb. The bomb ingredients themselves, notably liquid explosives, will be kept out of the cabin by a ban on liquids, gels and lotions, except for small amounts of baby formula and medications.