Back when I lived out there I had to deal with LAX's ridiculous post-9/11 security precautions. The worst one,
which they've brought back, was the banning of all private cars from the terminal area. Aside from the fact that the airport did not have a sufficient external parking/shuttle system to cope with even a fraction of the passengers, there was a minor hole in this plan - a hole big enough to drive a cab through. Cabs still had pretty unfettered access. And, given that concerns were and are primarily about Arab/Muslim terrorists, and every single cab in LA appears to be driven by recent Arab immigrants...