[pmontra]

Even if Google (or Facebook) are split into pieces many people will still do social logins, so no different accounts for different services. I don't do social login and I don't like the very idea of centralizing authentication and profile managment (probably also some of authorization) but I also don't think that there is any legal ground to forbid it.

[ocdtrekkie]

That actually will likely be a short-term solution if companies are forced to unbundle.

Say Google is required to sell Chrome and/or Android. Problem is, billion people's Google accounts are signed into those devices. Solution is, you replace the "Google account" on an Android device with an "Android account" that uses Google auth for login. Then, if a user wants after that point, they can detach that, set different credentials, whatever.