Here&#x27;s my guess: some of Google&#x27;s &#x2F; Alphabet&#x27;s nefarious practices include collecting information on users&#x27; previous pages. Fixing this bug the correct way (disabling window.opener by default when cross-origin) would put a dent on their cut, so they&#x27;re using their leading browser to try and influence how the rest of the world tackles this issue: putting the burden on developers means 99.99% of websites will remain open to this bug and to their data collection.<p>Time to find Firefox&#x27;s equivalent issue page and convince them not to follow the leader.