And yet-- I still believe it's wrong.
I have had numerous parents tell me that "everyone does it" and that if I can't give consequences to every kid who cheats, then I shouldn't punish their kid. The words "character," "honesty," and the like are laughed off as at best a quaint notion from bygone days.
In one previous incident, I watched a girl turn her paper so that the boy next to her could copy freely without straining his neck, poor thing. When I told her she got a zero too, she incredulously claimed that she hadn't been cheating. I held my ground with her and with her daddy, and fortunately was backed up by administration.
But the saddest part is that kids who don't bother to learn the material really cheat only themselves. Then they wonder why they struggle.