Do not put all your eggs in a basket
ID federations (single-sign-on services and password managers) create a single point of failure, not unlike putting all the eggs in a basket. It remembers all my passwords when un-hacked and loses all my passwords to criminals when hacked. And it is now demonstrated that we could be locked out. It could be considered mainly for low-security accounts, not for high-security business. Needless to say, the strength of the master-password is crucially important, if required in fewer numbers.
Biting the hand that feeds IT
