You're absolutely right in the sense of taking the shotgun approach. It's the international standards that we're trying to keep up with, and we can't be the weak link in that.
Behaviour observation is more of a single-shot approach, in the sense that you're looking at trying to pick out those individuals who could be potential hazards to security. That's one of the reasons we're doing the review. That's one of the reasons we added significant layers since the attack in December.