Green light for abuse of power

In the Guardian today, Jenni Russell has a column describing the danger you are in when you argue with a petty "public service" jobsworth:

One of them aggressively thrust a BAA [British Airports Authority] complaints leaflet into my hand, saying: "If you're so worried about it, you can fill in that form." I said that all I was interested in was the situation now. "There's no point talking to BAA because they won't do anything anyway," the younger one said. I said that was appalling, and could I take his name because I would raise it with BAA. No, he said, as he and his colleague immediately covered up their name badges.
"Look," I said, exasperated, raising my voice. "The sign behind you says you're here to help customers; why are you being so unhelpful?" "Right," said the older man, gleefully. "You're being threatening. I'm calling the police."
Within minutes, to my shock, two policemen were at my side. They were grave. One was suspicious; the other, eventually, sympathetic. But I was left, just as the BA [British Airways] staff had intended, feeling intimidated and powerless.

We are giving the authorities an open invitation to abuse their power