Why limit it to direct harm? There's tons of easily avoidable ways to indirectly cause harm. The most obvious to me are about our natural world: taking anything in an unsustainable way deprives others of opportunity, up to and including their ability to feed themself. Reckless hunting or fishing, poisoning water with agriculture runoff, introducing invasive species for personal gain or through negligence, even just cutting down all the trees around you can have loads of consequences with the impact to animal habitat and increased soil erosion.