Won't work! Sure bmi have more or less said the same thing, "food consumed on board must be purchased from the cabin crew and not brought on".
So does that mean if a passenger refuses to hand over food or drink brought on, that they're going to land the plane, chuck people off, and tell a couple of lazy english airport police that Mr so and so was eating Polo Mints, put him in jail!?
Next time I chew gum on board, let me tell you I'll chew it hard and I'll make sure they see me. What delight I'll take in shoving it right in thier hands!