Content Moderation on End-to-End Encrypted Systems: A Legal Analysis

8 Georgetown Law Technology Review 1 (2024)

92 Pages Posted: 25 May 2023 Last revised: 9 Jan 2024

See all articles by Charles Duan

Charles Duan

American University Washington College of Law

James Grimmelmann

Cornell Law School; Cornell Tech

Date Written: May 23, 2023


End-to-end encrypted online platforms are increasingly common in the digital ecosystem, found both in dedicated apps like Signal and widely adopted platforms like Android Messages. Though such encryption protects privacy and advances human rights, the law enforcement community and others have raised criticisms that end-to-end encryption shields bad behavior, preventing the platforms or government authorities from intercepting and responding to criminal activity, child exploitation, malware scams, and disinformation campaigns. At a time when major Internet platforms are under scrutiny for content moderation practices, the question of whether end-to-end encryption interferes with effective content moderation is of serious concern.

Computer science researchers have responded to this challenge with a suite of technologies that enable content moderation on end-to-end encrypted platforms. Are these new technologies legal? This Article analyzes these new technologies in light of several major federal communication privacy regimes: the Wiretap Act, the Stored Communications Act, and the Communications Assistance for Law Enforcement Act.

While generally we find that these content moderation technologies would pass muster under these statutes, the answers are not as clear-cut as one might hope. The advanced cryptographic techniques that these new content moderation strategies employ raise multiple unsettled questions of law under the communication privacy regimes considered. This legal uncertainty arises not because of the ambiguous ethical nature of the technologies themselves, but because the decades-old statutes failed to accommodate, or indeed contemplate, the innovations in cryptography that enable content moderation to coexist with encryption. To the extent that platforms are limited in their ability to moderate end-to-end encrypted content, then, those limits may arise not from the technology but from the law.

Keywords: Content Moderation, Online Platforms, Encryption, End-to-End Encryption, Law and Computer Science, Technology Law, Communications Law, Privacy, CFAA

JEL Classification: K14, K22, K23, L86, L96

Suggested Citation

Duan, Charles and Grimmelmann, James and Grimmelmann, James, Content Moderation on End-to-End Encrypted Systems: A Legal Analysis (May 23, 2023). 8 Georgetown Law Technology Review 1 (2024), Available at SSRN: or

Charles Duan (Contact Author)

American University Washington College of Law ( email )

4300 Nebraska Ave NW
Washington, DC 20016
United States

James Grimmelmann

Cornell Law School ( email )

Myron Taylor Hall
Cornell University
Ithaca, NY 14853-4901
United States

Cornell Tech ( email )

2 West Loop Road
New York, NY 10044
United States

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