In law "ignorance of the law is no excuse" so, regardless of how right/wrong it may appear for the OP's friend's to be taken to court, it's right that she's taken to court. However I'd be very surprised if the judge doesn't find in her favour TBH.
I doubt it, unless she has concrete evidence that some random person decided to steal her rubbish then I think that notion would get laughed out of court!
