There are very serious privacy and civil liberty issues of having people permanently numbered.

The court has . . . recognized that personal privacy is a component of the liberty protected by the due process clause, ... The court has explained that the liberty protected is not limited to freedom from physical restraint, and that it's protected not simply procedurally, but as a substantive matter as well.

We must protect our citizens' privacy -- the bulwark of personal liberty, the safeguard of individual creativity.

And get into your home or your computer, and potentially a secure door in your workplace.

There is a potential for a security problem.

It may seem innocuous, but the government and private corporations could use these devices to track people's movements. It may sound paranoid, but this is bound to be abused.