I used to live in Minneapolis, the city does not have aluminum can/glass bottle/plastic bottle recycling for cash like in a few other States. Well, you can get $ for cans but less than half of what you would get in, say, California, so practically no one does it (recycle for cash). Metal, however, was the thing to do.
The big thing thieves would go for were/are the copper pipes accessible through the basement of unoccupied homes.
Ironically, many businesses kept used kegs locked behind a chain link fence, outdoors.