While I find the details of this case distressing, customs are not total monsters.
I visited France with a friend recently, and on my return we were pulled over by customs - 2 youngish men, me the driver, blinking away (sun lotion I had put on, while sitting on deck of the ferry, had later got in my eye - at a very inopportune moment). To be fair, my blinking could have been taken to be a sign of drug use and/or nervousness, even though there was an innocent explanation. The reason for us being pulled over was not raised; a minor search took place. Neither of us were carrying anything illegal. In this case while it was worrying, I have to say customs were just doing their job.
Of course it was rather different in this Sabrina Johnson case...