I'm with you on the costs of continuing the "no carry-ons" policy.

Background checks for all passengers will never work. Most people have a vastly over-inflated view of what level of assurance you can get from a background check; in reality, they don't work anything like some people think. Background checks are not likely to be useful for passenger screening; the proposal is ill-informed.

The real problem here is unrealistic expectations about risk. If we look at the US, say, I suspect more people die each month in automobile accidents than have died due to terrorist attacks during the entire history of the US. Yet people get all worked up about terrorism and air safety, while thinking nothing of getting in the car and driving -- even though the latter activity is far more risky. People's perception of risk is all wacked, and as a result, they demand the impossible.