In IE10 Metro, navigating to a new URL briefly showed the address bar so the user could see where they were going. I found that using location.reload() with a server-side redirect to a different URL bypassed this behavior — the reload happened silently without the address bar appearing, making the user think they were still on the original site when they had actually been redirected to a completely different one.
// Server sets a cookie on first load.
// On reload, server reads cookie and redirects to bing.com.
var dt = new Date(); dt.setTime(dt.getTime() + 5000); // 5000 ms for cookie expiration.
document.cookie = 'reloaded = true;expires=' + dt.toGMTString();
location.reload(); // This reloads and redirects to Bing without showing the address-bar.
The server used a short-lived cookie to distinguish the first load from the reload. On the second request, it issued a redirect to a different domain. Because reloads did not trigger the Metro address bar visibility behavior, the user saw no indication that the URL had changed.
Found during my years at Microsoft (2006–2014). These bugs were patched long ago — shared here as a historical record for learning purposes.