Art thief, is the coffee shop liable too?

I was in a Coffee shop on Friday and noticed this artist was selling pictures of artists; Adele, The Clash, Prince, Rhianna, Eminem, and others. They were all clearly images made by others that he had manipulated slightly in a photo editing program, had printed on canvas or some other material, and was offering for sale from the coffee shop's walls. As an artist who creates all my own work and struggles to find a market I was taken aback at this obvious theft. First, of the original image maker's work and secondly of the artist depicted. If the AP-v-Shepard Fairey case taught us anything it is that stealing like this for profit is illegal. I don't think this guy will sell very many of his "paintings" but, even one sale is a theft.

What do you think?