MercExchange nailed eBay for patent infringement of 5,845,265, 6,085,176, & 6,202,051, implemented in eBay's "Buy it Now" feature, which lets shoppers halt an ongoing auction and buy an item at a fixed price. The appeals court sided with MercExchange, granting an injunction to stop eBay from using the feature, but staying the injunction pending an appeal by eBay to the Supreme Court. The Supreme Court case is about the rules by which an injunction may be granted. Current statutory and case law favor injunctive relief except in extraordinary circumstances, such as protecting public health.

The MercExchange v. eBay case is a reconsideration of the 1908 Continental Paper Bag Co. v. Eastern Paper Bag Co. case, which favored injunctive relief. The high court, in accepting eBay's petition for a hearing, asked both parties why it should reconsider the 1908 case.

Computer companies have naturally sided with eBay, wanting to water down patent enforcement so they can infringe without the threat of stopping product sales; basically a pay-to-play patent enforcement regime, where the only issue related to patent infringement is the price tag. The nut of eBay's argument is that "monetary damages are a perfectly adequate remedy" for patent holders who've been infringed upon. Inventors and the biotechnology/pharmaceutical industries, which rely upon patent protection to recoup the millions invested in discoveries, favor injunctive relief. The historical nature of the patent grant is exclusivity, not patent pay-to-play.

It can be difficult to discern how a judge may rule by tone, questions, or statements made during such sessions, as playing devil's advocate is a common technique. Then again, some justices wear their attitude on their sleeve.

Justice Antonin Scalia tore into eBay's argument that non-practicing inventors should be treated differently: "Why should we draw a distinction between the solo inventor who needs a patent speculation firm to market his invention and somebody else?" Scalia asked. "We're talking about a property right here, and a property right is the exclusive right to exclude others." Scalia voiced skepticism about the court altering existing patent law just "because we have renegade jurisdictions."

The federal government backs MercExchange in favoring injunctive relief, saying that injunctions "force negotiations between the parties" in a process that accelerates determining the real market value of the invention. If eBay can't use the feature unless it pays, we'll find out what the feature is worth to eBay. Justice Anthony Kennedy seemed to agree, stating that injunctions often prove to be the quickest way to settle patent lawsuits. And Scalia chimed in with, "Why isn't the free market adequate to resolve these problems?"

Justice Ruth Bader Ginsburg observed that making injunctions more difficult to obtain would amount to compulsory licensing, i.e., pay-to-play, a stance that Congress, in passing the Patent Act of 1952, had rejected.

A few justices seemed out of their depth at times. Young Chief Justice John Roberts had a senior moment: "What exactly is the invention here? It's not like an internal combustion engine. It's very vague. I might have been have been able to do that.'' But Roberts also expressed concern for inventors: "'the guy in his garage' who can't - or doesn't want to - build his invention." Justice Stephen Breyer wondered about the viability of business method patents: "Maybe A&P could patent its process for a supermarket." Justice Anthony Kennedy surreally asked, "Is the troll the scary thing under the bridge, or is it a fishing technique?"

Brian Ferguson of McDermott Will & Emery in Washington D.C. thinks eBay has already pulled the short straw: "the facts of this case still meet the standard for granting" an injunction.