While it seems a great idea to link an accomplice to a crime by reviewing the data of a Clipper card user, it does raise the issue of privacy concerns and what information is kept by the Metropolitan Transportation Commission (MTC) and Clipper, and how long they keep information about your usage.
While the Bay Citizen reported the number of warrants to release information was only a few (back in October 2012), the data Clipper gathers is typically used for assessment purposes by reviewing the riding patterns of the public. Without the need for people to have clipboards at bus stops, the Clipper card can keep track of the number of passengers that rides the vehicles, and at train stations and Golden Gate Transit, able to determine patterns of passengers of where they ride to and from. The data they gather helps transit agencies find if additional or less service is needed, or the need to operate higher capacity vehicles or trains due to boarding numbers.
Some transit agencies like Samtrans and Muni may know what route you took, but can't determine where you boarded or exited because they don't have GPS information connected to the Clipper devices; this is unlike Golden Gate Transit that operates on a zone system requiring GPS to determine your ride fare, and train stations that needs to know what station you boarded and where you exited to properly charge you the right fare.
Even then, the data retained tells a lot about your usage patterns. Is having a registered card risky? If you are a criminal, probably so. Grocery stores with self-checkouts sometimes have problem with theft by tricking the machines, but people are stupid enough to use their registered store loyalty card during the check-out process. But if you are a law abiding citizen and don't mind having your records kept for several years, then it's okay for you.
After the Bay Citizen reported about the issue, the state government scrambled to work on changing the policy from seven years of data retention to just three.
However, a law that was proposed in the senate would re-define the retention of data for those who cancel their Clipper and FasTrak accounts; the policy would be only up to six months from the date of cancellation of the account. Also, the senate law proposed would also: "Require deletion after six months of PII not needed "to perform account functions such as billing, account settlement, or enforcement activities.""
While six months sounds like a useful amount of time, the MTC did not agree on the six month policy because of the statute of limitations, so instead of six months or even three years, the most suitable amount of time would need to be longer.
Operations Committee of the MTC will be voting upon a proposal to change the retention of data this Friday:
- The MTC is proposing to change the data from seven years to four years and six months.
Shortening it to just slightly beyond the statute of limitations isn't such a bad idea. I'm not that concerned of my usage patterns, even with my grocery store loyalty cards. Like Safeway really cares if I made a purchase of ice cubes and condoms in one transaction.
But if you personally have a fear of the government tracking you, why not just get an unregistered Clipper card? Just make sure to replenish your card only using cash.