Agreed, it would be so simple to keep your belongings in sight if they wanted to. This is really a policy area since it involves installation planning & budgeting. Besides the degree of personal security that could be added, a lot of these checkpoints would benefit from a simple human factors analysis -- optimizing not only the flow of passengers & baggage into the system but even things like returning empty bins which now are done via cart and often doesn't happen until the lines are delayed. The same applies to checked baggage. Do the baggage inspection right in front of the customer, then offer the option to seal the luggage. Customers who don't want to watch the inspection could drop theirs off at an expedited/theft conveyor.