I ask this seriously: who cares? Literally -- who should be concerned about this? Mass data collection is no longer a surprise; it's simply another feature of the landscape at this point. Additionally, the notion that an individual in a public space (physical or virtual) has a reasonable expectation of privacy is not credible. It's reasonable to assume that you are being surveilled by (mostly benign) third parties in any public space; why would you expect that your virtual activities would be treated differently than your physical ones?

I do care, I'd like to know about surveillance (whether I can do something about it is secondary). Knowing may allow me to modify my behavior.

To your point about reasonable expectation of privacy. On the surface, yes, you do not have a reasonable expectation of privacy in public, however, I do not like the idea of having my picture tied to identifying information like a mac address. It starts to provide a fuller picture of a person and would allow more data in which to build up a profile.

At the end of the day I'd like to choose how and when my personal information is exposed (to the extent that I'm realistically able to control it)

From the Privacy Policy

INFORMATION COLLECTED BY OUR SENSORS AND CAMERAS ... We will not use facial recognition technology for any reason, and we will not use our cameras to track your movement through the city.

http://www1.nyc.gov/assets/doitt/downloads/pdf/Proposed-PCS-...