I've discovered that there are a few people out there who nip your art and do whatever they please with it. I won't mention who the ones I've found are, but unfortunately I have to be a little harsh in this post and once again state that my readers don't have permission to take my illustrations and make their own iphone case from sites like CaseApp. Buying your case from CaseApp costs 300 SEK and buying a case from my own shop Society6 costs 245 SEK and gives me a 23 SEK profit (before tax and other fees nip more from that sum). I don't make a lot of money from selling calendars or prints so it really sucks when I see that the copyright isn't respected.
I know there are many of you who DO respect it and this post does absolutely not apply to you :) But especially young people haven't really learned about the rights artists have to their work.