Wheely Bin

I saw this on my travels and my first thought was "this is odd, why padlock a bin, what's so valuable in a bin that it needs closing with a padlock and chain it's all rubbish." So I investigated. The valuable thing inside this wheely bin is empty space. Really. The owners of this bin pay the council good money to have their bin emptied as it's technically trade waste. Then they find everybody and his dog filling up their bin with household rubbish so there's no room left for theirs.
Meanwhile I find a friend of mine has just got her own spot on the Radio as a household chores Agony Aunt. That's cool. And the next caller please...