You don't have to be an asshole just because the other guy is a butthead

So I don't get to write all that much these days.  Half the time I'm typing one-handed anyway.  But I do get to read... often while standing and swaying, holding a Very Angry Baby.

And what I'm getting out of what I've been reading is pretty much "A does B to C" and if you think B might be a bad idea, you can read about how it's all okay because C is our enemy, or at least not A, who is either us or a friend, or a guy/country/religion in a cute bunny suit.  In fact, comments sections are full of people saying it's all okay to do B to C, because C does B to X,Y, and Z all the freaking time.

Now my mom once asked me if all my friends jumped off a bridge, would I jump too?

You could point out that C is not our friend, so this gem of a saying has no point, except...

If we wouldn't to do something we know to be wrong, even though all of our friends are doing it, why on Earth would we do something we know to be wrong because it's what our enemies do?