CC Attribution Noncommercial Sharealike with the add-on that I want a picture.

No, I mean, what law would they be in breach of if they don't send a picture?

I'm guessing you won't take anyone to court over it, but if you did, how would you do it?

I personally wouldn't take someone to court over this, a slap in the face is sufficient. But if I were to, my understanding is that it's copyright infringment:

http://cyberlaw.stanford.edu/blog/2008/10/breach-conditions-...