Crossover Point
All security is a trade-off between safety, cost and convenience in the sense of what can be tolerated. In other words, there is an acceptable level of risk that people are prepared to tolerate before the precautions themselves become intolerable.
It seems to me that we have reached the crossover point with the current restrictions on cabin luggage.
The key points revolve around electronic equipment, in particular laptops, mobile phones, PDAs. (Was it really only early last week that a furious debate was going on about the wisdom of allowing/facilitating the in-flight use of mobile phones?)
The simple fact is that business passengers in the 21st century expect to be able to take their laptop into the departure lounge and continue working in a relaxed atmosphere to kill those two hours of "security required" check-in time. They expect the airline to get both their person and their laptop to their destination undamaged. They might like to work on the plane, so they might reasonably expect to take their laptop with them, which also means at least the damage/loss criterion is their own responsibility.
Are we really saying that this is impossible to arrange?
If that is, indeed, what we are saying, then commercial air travel, supported by the premium business passenger, is doomed, at least with its current economic model.