That's a very good question, Madam Chair.
If I think about the level of risk of the individual person, we generally treat it as systemic. We look at the background check and the physical screening together. That's why we have this risk-based approach to who should be screened. In effect, then, yes.
We've done a lot of work to say what the relative risk is. Take, for example, the security director at the airport. Is it necessary to screen them every time they go in and out, five or six times a day?
That's part of what's built into the randomness. There are levels of risk built into it, but in general once someone has access to the system, we try not to micromanage that element. It is, however, built into the system.