The desire to enforce unique password across sites is understood. You might as well advocate all browsers to implement a builtin password manager a la LastPass

The desire to enforce unique password across sites is understood. You might as well advocate all browsers to implement a builtin password manager a la LastPass and a protocol to auto-gen a password (by the site to enforce cross-site uniqueness) to be managed by the password manager. Imagine zero password fiddling signups! Force a per site password policy on end users other than length is super annoying. The worst kind are those who restrict you to use only alpha-numeric passwords. Down with manual password policies!