Stealing someone else's work

Today I stumbled upon a mail order cake site based in India. Apparently they've been using images from my portfolio and claim it theirs. I also discovered that they've got images from other cake sites too. Do they not even capable taking picture of their own work ?
Is it just a lazyness because it is so easy just take other's work, copy them and sell them cheap?

I don't mine people use images on my sites for design inspiration, but please don't just copy it and claim it yours. I really don't know how to react in this situation.