I've run into people bringing this up when discussing hobbies and activities that to my mind don't violate anything in scriptures, and they can't cite any other verses, (I once had someone used this to argue watching the original Star Wars was sinful). I know we shouldn't put a stumbling block for others(kind of dependent on being aware of someone's potential weakness), and pursuing things that don't profit(presumably meaning don't let it it become an idol, or let it consume too much of your time). Then there's the obvious point about not violating your own conscious.
My point is, isn't this largely a personal standard? How should one handle an accusatory situation?