Vancouver PD website features Quick Escape button that wipes itself from history

Original Article ↗ Hacker News Discussion ↗

Vancouver’s police website now includes a “quick escape” feature that instantly redirects visitors to benign sites like Google or a weather page and renames the tab, aiming to help people in abusive or unsafe situations hide their activity. Commenters examine how it works technically—using `window.location.replace` and visual tricks—and point out its limitations, such as residual history entries, back-button behavior, and other browser traces. The feature is compared with similar patterns on government and support sites worldwide, sparking broader questions about safer browser defaults, incognito modes, and whether websites should be able to alter history entries at all.

Implementation of the “Quick Escape” Feature

  • VPD’s button hides the page by setting body opacity to 0, changing the title to “New Tab,” opening a neutral site (weather), and using window.location.replace to overwrite the current history entry with Google.
  • Some suggest randomizing destination URLs and blanking the DOM (innerHTML = '') instead of only hiding it, to avoid a visual “flash” and speed concealment.
  • The feature does not fully erase traces: previous pages in the same session remain in history, the tab can be reopened with Ctrl+Shift+T in some browsers, and in some environments it doesn’t work as intended (e.g., Safari back button, Android-based browsers).

Privacy, Traces, and Abuse Threat Model

  • Users point out that cookies, local/session storage, IndexedDB, caches, and even favicon caches can persist, and that abusers may use tools to inspect this, not just browser history.
  • Others note VPD’s site appears not to store anything in browser storage, but favicon/history artifacts can still remain.
  • Some argue that even if 99% of abusers don’t check these details, the feature must account for the 1% who do.

Browser Capabilities and Security Concerns

  • Debate over whether sites should be able to alter history entries at all; some see location.replace as a long-standing, legitimate feature, others as a “misfeature” ripe for abuse (e.g., spoofed history entries like “Amaz0n”).
  • Conflicting views: one side says cross-site replacement is not a major risk and has existed since the 1990s; others see potential for framing or deceptive histories.

Alternatives: Incognito, Guest Mode, and System Shortcuts

  • Suggestions: use private/incognito windows, guest profiles, Alt+F4, or OS-level app switching instead of site-specific escape buttons.
  • Counterpoint: private mode requires advance planning; victims may not know about it, may be on locked-down devices, or may be caught suddenly.
  • Some note that incognito’s dark theme and other visual cues can be conspicuous; Firefox has a config flag to disable dark private windows.

Other Implementations and UX Patterns

  • Similar features exist on domestic violence, mental health, and LGBTQ support sites (e.g., hotkeys like triple ESC).
  • The UK government’s “Exit this page” pattern (triple Shift) and New Zealand’s “Shielded Site” iframe are cited as more thought-through, history-minimizing approaches.
  • UX concern: in a panic, adding a special button or key combo may increase cognitive load versus users relying on familiar device actions; effectiveness is considered unclear.