The Supreme Court heard oral argument today in another patent case, Limelight Networks, Inc. v. Akamai Technologies, Inc. In this case, the Court considers what to do when one party performs some steps of a patented method and another party performs the remaining steps. Specifically, Akamai wants to hold Limelight liable for patent infringement even though its customers perform one of the steps of the patent (i.e. four steps are performed by Limelight, one by the customers). The Federal Circuit had ruled for Akamai and effectively held Limelight responsible for the actions of its customers.

In our amicus brief, we explained this ruling for Akamai could expand patent liability by placing at risk anyone who performs even a single step of any patent claim. The ramifications of such a change are extraordinary: depending on how a claim is drafted, any downstream user of a technology—such as a Limelight customer who tags his content—could find herself liable for infringement. This is part of a larger problem with the patent system where trolls and other abusers take already overbroad and vague patent claims and use them to shake down everyone from startups to nonprofits to innocent consumers.

Reviewing today’s transcript, it seemed clear that the justices shared the same concerns. Arguing for the patent owner, prominent Supreme Court advocate Seth Waxman tried to downplay any risk to customers. One exchange in particular jumped out:

MR. WAXMAN:  ... Consumers aren't sued under patent law for infringement, whether there's a single user or multiple users.

JUSTICE KENNEDY: Yet, until we issue the case in your favor.

MR. WAXMAN: No, no, not at all. Quite to the contrary. The consumer -- first of all, consumers aren't sued, because under the patent law, under like -- under -- unlike copyright law, there are no liquidated damages. No one sues individual consumers

Unfortunately, no one corrected Mr. Waxman’s bald, and totally false, statement. Not only are consumers sued for patent infringement, but recent years have seen an explosion in suits against end-users of technology products.

Patent trolls have sued or threatened to sue tens of thousands of end-users. For example, Innovatio attacked cafes, bakeries, and even a funeral parlor for using off-the-shelf Wi-Fi routers. And the notorious scanner troll, MPHJ, targeted small businesses and nonprofits around the country for using ordinary office equipment. As a recent paper explained: “Mass suits against technology customers have become too common, involving building block technologies like wi-fi, scanning, email and website technologies.”

The growth in patent suits against customers reveals the importance of the Limelight case. A ruling that made it even easier to sue customers (by allowing suits against someone who performs just some steps of a patent) would encourage patent trolls to launch more abusive litigation campaigns. We hope the Supreme Court will restore the sensible rule that only a single entity (or its agents) can infringe a patent.