Shawn Hirn wrote:

"Passengers are requested to inform the crew of any suspicious
behavior they see or may be called upon by crew to subdue or
incapacitate persons that are threatening the safety and security
of the aircraft."

Would that have prevented this latest incident?

Has anything done since 9/11 prevented the shoe bomber or now this
crotch bomber from getting on a plane?

It doesn't cost any money, it doesn't waste anyone's time or cause any
inconveinence to include that additional sentence in the pre-flight
announcement. It's effectiveness at causing stress and anxiety for
those conducting planning of a terror act and those attempting to carry
it out can't be under-estimated. It might be enough to cause them to
slip up or botch the attempt.

If the guy was just sitting at the gate waiting to board like
all the other passengers, I doubt he exhibited any unusual
behavior.

The announcement I'm talking about would not be played at the gate. It
would be included as part of the pre-flight crap you hear once you're
already seated on the plane.