I bet they are very reliable. Just look at the immigration hall of the average international US airport and you'll quickly realize that it is literally impossible for even a fraction of the people going through there to be physically searched. Of course this applies only to the average visitor and I'm sure you can significantly increase your changes by being the the "right" line of work - but from my experience and the people I know and work with, being in "IT" in general is not enough to get you searched.