http://en.wikiquote.org/wiki/Benjamin_Franklin
Without the word "essential", this quote sounds very absolute and idealistic, which was of course not the intention.
Heck leave alone our country men and their talent at finding loopholes or the corruption of our system.
When I know first hand that the debate internally amongst the world bank and nandan nilekani went from trying to tackle the privacy issues to "my role is to give every Indian a number" (second hand quote) my hair stands on end.
Not to mention that the system already creates duplicates and overlaps, which then compound which each subsequent generation.
Or the fact that we already have bad data from outsourcers who just jammed info into the system, or the fact that the laptops were stolen. I think we lost data recently too.
This is just a bad idea.
In terms of liberty - a biometric id is, by definition, an "involuntary" identity. It's something you're unable to change or refuse to yield, even if you choose to. A person with a non-biometric identity can freely destroy all forms of that identity and then they cannot be identified any more by it. They have the freedom to produce it when they wish to be identified, and to choose not to when they wish to remain anonymous. A biometric identity is a non "opt out" identity. It can never be changed or altered, and can be forcibly read by anybody with physical control over you. Hence there is a great loss of liberty in a biometric identity, and when you really think it through, almost no advantages that can't be obtained from a non-biometric identity.