Do you have any ideas?

In Norfolk we pay for a brown garden waste bin. It costs about £42 a year, and the men will not pick it up unless you have paid and you are on the list.
A friend of mine, who is over 80 has had hers stolen and apparently someone close by has also had hers stolen.
The council will replace them free of charge.
But why would someone steal one, the only thing I can think is they are foreign students from the local university who think they automatically get picked up, if you leave one outside your house, even without paying, but this is not the case.
Do you have any ideas?
A friend of mine, who is over 80 has had hers stolen and apparently someone close by has also had hers stolen.
The council will replace them free of charge.
But why would someone steal one, the only thing I can think is they are foreign students from the local university who think they automatically get picked up, if you leave one outside your house, even without paying, but this is not the case.
Do you have any ideas?