Double whammy black eye for the police
QUOTE
MacGregor told the Beeb last night that there were "grounds for doubts" about the reliability of facial recognition tech.
UNQUOTE
Quite right.
There's lots of evidence that the technology doesn't work, – http://www.theregister.co.uk/2009/08/14/biometric_id_delusion/ – and no evidence that it does.
Not just an invasion of privacy but also a waste of money. The police may want to be seen to be "doing something" but this is a double whammy black eye and not a feather in the cap at all (Catch-22).