US Senator Al Franken has waded into controversy over Apple's Touch ID biometric system on the iPhone 5s, challenging the Cupertino firm to address his security concerns about stolen fingerprints and data privacy. In an open letter to Apple
CEO Tim Cook - in which he's quick to point out that he himself uses an iPhone - Senator Franken highlights the fact that fingerprints, unlike a password, cannot be changed by the individual. "You have only ten of them" the senator writes, "and you leave them on everything you touch; they are definitely not a secret." However, while the letter makes some reference to Apple's already public security measures
, it also seems to confuse exactly which part of the finger Touch ID is assessing.