This posts is over 3 years old, and there is a way to report clans in-game now: Click on a player's name, go to "inspect clan" then you should see the ghost icon near the top right corner, click on that and there should be an option to report them. It only works on the second game and I'm on the Xbox One, so it might be a little different on the PS4 and PC. I was going to edit this in my post, but I can't since a post in this thread has been marked as the answer to my original question.