Re: I wonder how they got this information?
It's called "security theatre" for a reason.
The TSA and others have to be seen to be doing something. All this is achieving is the removal of those who "may" have travelled to the US for tourism/work/whatever and adding to the pain of flying.
The TSA is always trying to stop the last terrorist attack, it can only guess at the next.
If the flight is suddenly terrorism proof, then the next best thing to do would be to simply destroy the airport. Not in an inept way like Glasgow. Airports are insecure land-side with thousands of people, all with a legitimate reason to carry massive suitcases.
It serves no purpose. It's the same as me saying that the Tiger repellent I have on my desk here in the West Midlands is awesome, I've had it on for three years and there has not been one tiger related incident near my desk.
Agreed, there must be some security, but there needs to be a balance. At the moment the terrorists have, essentially, won due to the way we spend so much money and time chasing shadows. Moreover some of this nonsense INCREASES the risk. I have to leave my bag unlocked if I travel to the US. How hard would it be for a nefarious baggage handler to pop a device, bag of cocaine etc into every bag passing through? When stopped by customs in the US and asked if anyone had interfered with my luggage my honest answer was "I have no idea, I have to leave it unlocked and out of my sight for hours. Anyone at start or destination could have put anything in there." Luckily nothing had been added, but the comment earned me a world of pain and a coincidental "SSSS" added to all my boarding cards after that.