As a lawyer, the EFF's response was a thing of fucking beauty. Someone had a lot of fun composing that.
"Dear Zillow: First, not your pictures. Either the photographer's or the real estate agent's. Second, fair use exists. Look it up, shitheads, because my client's work fits ALL THREE categories. Third: even ignoring the above, you haven't proved that my client's work has affected sales of your shitty houses. So no damages for you. Finally, have half a page of footnotes from previous shitheads who have been spanked in court for pulling the same shit you're trying on. Yours faithfully."
Did they mention SLAPP in there? I can't remember.