Eric King recently posted a link to London’s Oyster Card FAQ page explaining Transport for London’s policy on requests for information from police — it rejects 5-10% of requests for providing insufficient information.
It inspired me to look up Clipper Card’s policy. As I suspected, it doesn’t report any similar numbers, but it says in its FAQ that:
personal information will not be disclosed to third parties, except as required by law, ordered by a court of competent jurisdiction, or where the express written consent of the Clipper cardholder has been obtained.
Even though there’s no obvious policy, MTA info has been publicly used in police proceedings. In 2008 it made the front page of the New York Times when MetroCard data got a suspect off of murder charges. An MTA employee in the article is quoted as saying that there would be a three-month wait time to retrieve the evidence, because “We’re very busy. We’ve got all these requests.”
(Interestingly, it didn’t make the front page when the charge was actually dropped, but the same reporter covered it for the New York section of the paper and the City Room blog. The two articles were released on the evening of New Year’s Eve 2008, and are nearly identical. One of the only differences is a sentence omitted from the blog post version, saying “The transit agency says it receives periodic requests to trace information.”)
This information seems to be a nice target for public records requests. Let me know if you’re interested in initiating some of those.