I am as left as you get.
Registered democrat since the age of 18. Atheist and graduated from college in the late 80s. 
I am just opinionated.
Anything can be justified, but some things are below my standards. I don't like damaging people who don't deserve it, but I still make exceptions if I'm particularly bored. Really, right and wrong are fluid for me, and whatever suits my needs at the time will do. Awesome.
Man created the idea of morals based on feelings and the drive for self/familial preservation. He established governments to enforce these ideas. Things that go against laws are criminal and one should avoid committing or being caught committing such acts, for his own good.
by WW2there are stupid things, irrelevant things and good things. only the stupid ones i dislike.
so you can rape/kill/w/e and depending on why, when, where and how, i might or might not give a shit.
Based on what do you give or not give a shit? Rules? Whim of the moment?
It's closer to whim of the moment in my case, and I think in most people's case. My moral compass, whose rules I haven't deciphered yet, or even payed too much attention to. Same or similar circumstances can trigger my "outrage" or not. It's not very logical. Sometimes the slightliest injustice, like someone not returning a lost wallet with ID to the owner, angers me. Other times I can watch or even make really bad fucked up things happen to someone I dislike/have clashed with, and not bat an eyelid.
if you do it on a whimp, its only stupid if you are not ready for the consequences, mentally ready. in other words, do not break down because of the consequences your actions. and do not lie to yourself to make it better. its stupid to lie to yourself and its stupid to do things you are not mentally prepared for.