Private Browsing 2.0

Original Article ↗ Hacker News Discussion ↗

Apple’s revamped “Private Browsing 2.0” in Safari adds stricter anti-tracking measures like blocking known trackers, limiting fingerprinting, cleaning tracking parameters from URLs, and proxying some traffic through a multi-hop relay. Commenters welcome stronger protections but are sharply split over Apple’s decision to include privacy-preserving ad attribution in private mode, with many arguing that a browser should not assist advertisers at all. There is also debate over how much iCloud Private Relay and similar features can really be trusted compared to ISPs, Tor, or alternative browsers like Firefox and Brave.

Ad attribution in “Private” mode

  • Many are alarmed that Web AdAttributionKit is now active in Private Browsing.
  • Critics argue: private mode should “do nothing for advertisers,” not spend user resources on ad measurement.
  • Some see this as capitulation to adtech; others argue it’s a constrained, “privacy-preserving” alternative to worse tracking, and that sites need some ad analytics to survive.
  • Debate over whether this is “worse for privacy”:
    • One side: before, private mode had no ad attribution at all; now it does.
    • Other side: it replaces more invasive techniques and doesn’t track individuals.

Tracking, fingerprinting, and GDPR

  • Discussion of fingerprinting: only 20–30 bits of entropy plus IP can uniquely identify users; even “cookieless” systems can track.
  • Some note this is likely not GDPR-compliant, but enforcement is seen as weak.
  • New Safari protections claim to blunt behavior-based signals (typing speed, cursor movement) and add canvas noise; concern this may break games or web photo editing.

Proxying HTTP and DNS; who to trust

  • Safari’s multi-hop proxy for unencrypted HTTP and DNS splits knowledge between Apple and a CDN provider.
  • Some trust this more than ISPs; others explicitly trust their ISP more than Apple/US companies.
  • Comparisons to Tor: more hops and jurisdiction diversity, but still vulnerable to global traffic analysis.
  • Disagreement about whether this model increases practical deanonymization risk vs. plain HTTP through an ISP.

Private Browsing semantics

  • Several note original “private mode” was about hiding history from local device users, not network/website tracking.
  • Expectations have shifted; now people assume strong online privacy, leading to confusion and lawsuits.

Extension breakage and site compatibility

  • Advanced tracking protection can break Safari extensions that rely on full URLs.
  • Some expect these protections will also break sites, but see that as an acceptable tradeoff.

Comparisons and alternatives

  • Firefox lauded for built-in first-party data whitelisting and cookie auto-delete patterns.
  • Brave and Firefox’s own ad-measurement features mentioned; Firefox enables a “privacy-preserving ad measurement” option by default but lets users disable it.

General sentiment

  • Mixed: appreciation for Apple’s privacy work overall, but strong discomfort that even Private Browsing now includes any ad attribution.