I remember as a child in the early fifties, my mother always had a coffee can on the stove where she would pour excess fat from the frying pan. No longer for turn in, but "waste not--want not," used it instead of store-bought lard. Old habits die hard.
If this country had half the sense it used to have, this "stealing" would be unnecessary, as it would have been folded into the free market, like other successful recycling and scavenging.