Overview of Universal Opt-Out Mechanisms for Web Tracking
Web servers and the entities that operate them have long had the ability to track user agents as they access resources hosted across different web domains. Concern over the privacy implications of such tracking has prompted recent work on a number of solutions that aim to provide a universal opt-out mechanism for web tracking that can be effectuated through a simple binary choice presented to users.
This document provides an overview of the following mechanisms: permanent opt-out cookies, cookie blocking, domain blocking, a “Do Not Track” (DNT) HTTP header, and a Do Not Track Document Object Model (DOM) property. The aim of this document is to describe each approach, the pros and cons of each, and areas where standardization may be necessary should each approach be further pursued, without making recommendations about which approach or approaches should be adopted.
Coalition Urges Senate Not to Let Companies Waive Financial Regulations for AI
CDT joined AI Now Institute, American Civil Liberties Union, and several organizations dedicated to tech policy, consumer protection, and civil rights in a letter to Senate leadership and the Senate Banking, Housing, and Urban Affairs Committee opposing the “AI Innovation Labs” language in Sec. 10509 of the CLARITY Act.
CDT and Partners Urge Passage of the California Location Privacy Act of 2025 (AB 322)
Location data is particularly sensitive, and when collected across time it can reveal a broad range of intrusive insights such as medical conditions, sexual orientation, political activities, and religious beliefs.
CDT and Allies Urge FCC Not to Violate Privacy of Cell Phone Buyers
CDT and EPIC led a coalition of 15 organizations in urging the FCC not to require phone companies to collect government IDs, physical addresses, and alternate phone numbers from every phone subscriber in the country.
