So I've recently had a couple of instances of people reporting some of my art being used/posted for different things around the interwebs. I have no problem with you guys using my artwork for non-profit purposes. My only request is that you credit me and link back to either my tumblr or DA account when you do so. If you don't credit an artist in some way, even just saying "this isn't mine" people are going to assume you're the artist. Plus its only fair to your followers that if they like a piece of art and want to see more of that artists works they don't have to go on an epic scavenger hunt.
The only thing you can't use my art for is profit. So no printing out some of my stuff and trying to sell it. Other than that go for it.