SESTA and the Teachings of Intermediary Liability

19 Pages Posted: 12 Feb 2018

See all articles by Daphne Keller

Daphne Keller

Stanford Cyber Policy Center, Freeman Spogli Institute

Date Written: November 2, 2017


This Stanford Center for Internet and Society White Paper uses proposed US legislation, SESTA, as a starting point for an overview of Intermediary Liability models -- and their consequences. It draws on law and experience from both the US and countries that have adopted different models, and recommends specific improvements for SESTA and similar proposed legislation.

Intermediary liability law, which defines platforms' legal responsibility for content posted by Internet users, shapes our real-world exercise of free expression and information rights. Laws that disregard the teachings of intermediary liability -- like SESTA -- will hurt both online speech and small platforms. This harm isn't necessary. Better crafted laws could achieve SESTA's goals with far less collateral damage.

* * *

SESTA, the Stop Enabling Sex Traffickers Act, would overhaul US intermediary liability law and potentially expose hundreds of thousands of US platforms to new civil and criminal claims. Its exact legal consequences are uncertain, because the bill is so badly drafted that no one can agree on its meaning. But SESTA’s confusing language and poor policy choices, combined with platforms’ natural incentive to avoid legal risk, make its likely practical consequences all too clear. It will give platforms reason to err on the side of removing Internet users’ speech in response to any controversy – and in response to false or mistaken allegations, which are often levied against online speech. It will also make platforms that want to weed out bad user generated content think twice, since such efforts could increase their overall legal exposure.

SESTA would fall short on both of intermediary liability law’s core goals: getting illegal content down from the Internet, and keeping legal speech up. It may not survive the inevitable First Amendment challenge if it becomes law. That’s a shame. Preventing online sex trafficking is an important goal, and one that any reasonable participant in the SESTA discussion shares. There is no perfect law for doing that, but there are laws that could do better than SESTA -- and with far less harm to ordinary Internet users. Twenty years of intermediary liability lawmaking, in the US and around the world, has provided valuable lessons that could guide Congress in creating a more viable law.

Keywords: SESTA, FOSTA, CDA, 230, speech, expression, platform, intermediary, Internet, trafficking, removal, takedown

Suggested Citation

Keller, Daphne, SESTA and the Teachings of Intermediary Liability (November 2, 2017). Available at SSRN: or

Daphne Keller (Contact Author)

Stanford Cyber Policy Center, Freeman Spogli Institute ( email )

Encina Hall, 616 Jane Stanford Way
Stanford, CA CA 94305
United States
6507234581 (Phone)


Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics