In Firefox, check for "Private Browsing" in the titlebar. In Tor Browser… default to "it's private". In stock Chromium, look for the string "Incognito" near the

In Firefox, check for "Private Browsing" in the titlebar. In Tor Browser… default to "it's private". In stock Chromium, look for the string "Incognito" near the Chrome hamburger icon (e.g. via IAccessible2). It's not hard to support this functionality in the major browsers: it'd take me all of 15 minutes.