Hacker News on 6 August 2021

• An Open Letter Against Apple's Privacy-Invasive Content Scanning Technology
• CalyxOS – De-Googled Android Alternative
• On Apple’s “Expanded Protections for Children” – A Personal Story
• The Problem with Perceptual Hashes
• Surveys show Americans want more walkable cities
• New UUID Formats – IETF Draft
• Scientist says cleaning indoor air could make us healthier and smarter
• Apple’s new abuse prevention system: an antritust/competition point of view
• U.S. FTC says Facebook misused privacy decree to shut down ad research
• Reflections on 10k Hours of Programming