I will blow my anonymity by linking to this:
https://www.youtube.com/watch?v=-vC9GSGUz3UWhile collecting fuel for the campfire, and doing a general cleaning-up of rubbish (much of which can also be used for fuel), I found two full butane fuel cans. It's a Bad Idea to leave them be, in case of bushfires; I didn't want them myself; and putting them in the provided rubbish bins was another Bad Idea (..as setting garbage trucks on fire is).
So.. a bit of controlled disposal was called for. :D