What is the most immoral thing you can do that does not involve other people?

Hypothetically speaking of course.<br><br>I will break the rules and answer the question. I think it's immoral to kill an animal. Why on earth would you do that? I can't see a good reason.<br><br>It seems to me that being immoral is doing things that are detrimental to the well-being of the world, or, to put it another way, detrimental to the majority of the people in it. <br><br>What other things are there? What do you think?