Real Safety AI Foundation / Research

Disability, Accessibility, and Civil Rights

The Moving Target: Unilateral Modification, Illusory Promises, and Assent to a Continuously Changing Consumer Interface

Publisher: Real Safety AI Foundation

Working draft. Not peer reviewed.

Written
June 2026
Version
v0.1
Pages
17
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Abstract

A consumer who taps I accept and begins using an online service is told, when a dispute arises, that the act of acceptance bound the consumer to the provider’s terms. This article concedes the point and asks the question that survives it. If acceptance binds, acceptance to what? Modern consumer interfaces do not hold still. The provider reserves the right to amend its terms at any time, and the interface through which the bargain is actually experienced, the advertising controls, the reporting paths, the placement of the operative buttons, changes continuously, often without notice and without any corresponding update to the agreement. The provider’s own documentation frequently fails to describe its own product consistently. This article argues that even granting valid assent at formation, an agreement of this kind fails on three independent contract grounds and one consumer-protection ground. A promise the provider may modify at will, including retroactively and effective on posting, is illusory. Changes delivered without notice do not bind the party who never saw them. An agreement whose terms and interface reflow continuously, and which the provider cannot describe consistently, lacks the definiteness a contract requires. And the arrangement is unconscionable, with its central cost, the cost of relearning a moving target, falling hardest on users whose disabilities impair the executive function and working memory that relearning demands. The provider’s escape from each defect is a single clause, the reserved right to amend; that clause is separately contestable on assent grounds, but this article does not rely on that challenge. It grants assent and shows the agreement fails anyway.

Keywords

  • unilateral modification
  • illusory promise
  • mutuality of obligation
  • browsewrap
  • clickwrap
  • constructive notice
  • definiteness
  • unconscionability
  • dark patterns
  • standard-form consumer contracts

Plain language slides

First slide of the plain language summary of The Moving Target: Unilateral Modification, Illusory Promises, and Assent to a Continuously Changing Consumer InterfaceOpen the 14-slide summary (PDF)

Suggested citation

Gilly, Travis. "The Moving Target: Unilateral Modification, Illusory Promises, and Assent to a Continuously Changing Consumer Interface." Real Safety AI Foundation Working Draft, June 2026. https://realsafetyai.org/research/moving-target/

Other versions

This paper is also posted on SSRN.

SSRN version

References (14)

This paper cites its sources in footnotes. Each authority is listed once, where it is first cited, with its footnote number.

  1. Footnote 2.Jamie Luguri & Lior Jacob Strahilevitz, Shining a Light on Dark Patterns, 13 J. Legal Analysis 43, 43–44 (2021).
  2. Footnote 6.Arunesh Mathur et al., Dark Patterns at Scale: Findings from a Crawl of 11K Shopping Websites, 3 Proc. ACM on Hum.-Comput. Interaction (CSCW) (2019).
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  5. Footnote 10.Harris v. Blockbuster, Inc., 622 F. Supp. 2d 396 (N.D. Tex. 2009).
  6. Footnote 12.In re Zappos.com, Inc., 893 F. Supp. 2d 1058 (D. Nev. 2012).
  7. Footnote 14.Douglas v. U.S. Dist. Court ex rel.
  8. Footnote 14.Talk Am., Inc., 495 F.3d 1062 (9th Cir. 2007).
  9. Footnote 17.Comb v. PayPal, Inc., 218 F. Supp. 2d 1165 (N.D. Cal. 2002).
  10. Footnote 20.Meyer v. Uber Techs., Inc., 868 F.3d 66 (2d Cir. 2017).
  11. Footnote 21.Specht v. Netscape Commc’ns Corp., 306 F.3d 17 (2d Cir. 2002).
  12. Footnote 22.Nguyen v. Barnes & Noble Inc., 763 F.3d 1171 (9th Cir. 2014).
  13. Footnote 23.Sgouros v. TransUnion Corp., 817 F.3d 1029 (7th Cir. 2016).
  14. Footnote 24.Berkson v. Gogo LLC, 97 F. Supp. 3d 359 (E.D.N.Y. 2015).

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