Famous LAST words? I hope they never come back to haunt him.
Provided that the pictures are stored anonymously and "cold hits" are ignored [and there will most likely be so many of them that it should be obvious that they should be] I don't really see any intrusion of privacy here. If someone sees someone's face, the only thing they'll know is that the person pictured has or at some point had a state ID card of some sort. If names, addresses, etc. were distributed with the photos, or if "cold hits" were pursued, that would be another matter. If the function, however, is to provide "negative controls" for line-ups, however, the larger the sample population the less intrusive for anyone and the fairer for any criminal defendant.