In my mind, there are (at least) two types of data mining that could be done with the MBs. One is "John Doe was at points A, B, and C, for X, Y, and Z minutes." Another is "Guest #1257B was at points A, B, and C, for X, Y, and Z minutes." To me, these are two very different pieces of information. The first is tracking a specific guest, most likely with the hopes of tailoring future offers to them. The second is more of a "traffic monitoring" device--see how many people go in what directions, and how long they do various things. I really don't have a problem with the second type. Even the first is something that doesn't necessarily get me riled up.
Do we even know what (if anything) Disney is doing with any potential data? Until they come out and say (or demonstrate) otherwise, I just can't get all worked up about this.
(Side note: my state has gone on the record as saying they use anonymous cell phone signals in an effort to track traffic. By combining several of these start/end calculations, they can come up with average drive times that they post on message boards in strategic locations along the highway. This is just another example of us being "tracked" without knowing (or caring?)."