What is Picket Fence Preview and how/why did they try to stop Zillow's FSBO lead routing?

Picket Fence Preview is a website and magazine dedicated to listing Vermont for sale by owners. They offer customers the ability to list there property on their website and magazine for a small fee. They also market/brand the concept that all leads/calls will be directly routed to them allowing you to find a unrepresented buyer and thus avoid all the broker fees! Unfortunantly most owners need more exposure than just Picket Fence so they end up posting their property on Zillow which messes up the whole leads routed directly to you thing. So, Picket Fence decided to sue ZIllow to stop their lead routing practices.