gstatic.com is a cookieless domain. The persistent push connection needed by FCM (like APNS on iPhones) can tie the IP to a specific account, so this captive po

gstatic.com is a cookieless domain. The persistent push connection needed by FCM (like APNS on iPhones) can tie the IP to a specific account, so this captive portal check gives them less information than they already have. Luckily on Android, you can use UnifiedPush and run your own push server to gain actual privacy.