Prompt injection is the SQL injection of the LLM era — easy to demonstrate, hard to fully defend against, and present in essentially every commercial LLM application. Here is what it is, why it persists, and the realistic mitigation playbook.

Differential privacy is the mathematical technique that lets a company compute aggregate statistics over its users while provably bounding what can be learned about any individual. Apple, Google, and the US Census Bureau use it. Here is how it actually works, where the guarantee holds, and where it fails.

The two mobile operating systems have arrived at recognisably different privacy postures over the past five years. Apple’s App Tracking Transparency, Google’s Privacy Sandbox, and the steady accretion of features in both have produced a comparison that is still close — but no longer symmetric.

Every connection on the internet starts with a DNS lookup, and for most of the internet’s history those lookups have been completely unencrypted. The shift to encrypted DNS — DoH, DoT, ECH — is one of the quieter but most consequential privacy upgrades of the decade.

Virtual Private Networks are aggressively marketed as solving privacy and security problems they often do not solve. Here is what a VPN actually does, the realistic threat model where it helps, and how to evaluate which providers are credible in 2026.

Even with all cookies blocked and all trackers disabled, the browser leaks enough information to be uniquely identified across the web. Browser fingerprinting is the surveillance technology that makes “private browsing” much less private than the name suggests.

The Right to Be Forgotten gives EU residents a real and unevenly applied power to remove search-engine results about themselves. Here is what the law actually allows, what Google approves and rejects, and the practical steps for filing a delisting request.

The web tracks you in ways that have outgrown the simple cookie. Tracking pixels, postback URLs, server-side conversion APIs, identity graphs, and CNAME cloaking all live alongside browser fingerprinting and the dying third-party cookie. A field guide.

End-to-end encryption is the most important consumer-facing privacy technology of the past decade. It is also widely misunderstood: what it protects, what it does not, how the major messaging apps actually implement it, and where the metadata still leaks.

There are roughly 4,000 data brokers in the United States holding detailed dossiers on virtually every adult. They are largely unregulated, mostly invisible, and surprisingly hard to remove yourself from. Here is how the industry works and the realistic playbook for opting out.