Needless to say, that's raising eyebrows among privacy advocates. The ACLU's Matt Cagle warns KQED that the airport could become a "honeypot" for police wanting to collect information about anyone paying a visit, whether or not they're suspected of committing a crime. Also, it's not clear why SFO needs to preserve all that license plate data for so long. If there isn't reason to hold on to plate info (whether for crime reports or long-term parking), shouldn't it be erased within a matter of days?
In theory, this is legal: the airport implemented its new policy in response to a law that required public disclosure and security measures for license plate data collection. The very act of scooping up license plates is theoretically legal, then. The question is whether or not SFO is managing that info in a responsible way, and it's not clear that this is the case. About 53 million passengers go through the airport every year, and many of them drive to get there. While this could help catch car thieves and terrorists, it could also help less scrupulous authorities track the movements of activists and other innocents.