> I see very little possible misuse of temperature preference (of all things...) and very great possible gains.
That's where the problem lies: the greatest gains should come from features/sensors/products not yet introduced. Of course temperature preference is a very weak data point for privacy, but I can think of a few invasive things a future device could have. I don't know if that's actually possible with a device in that price point, but if a thermostat could know who is in a room, there's a lot of good/evil that could be done with that data.
It would make it really easy for the DEA to figure out who the home pot growers are. Yeah you can look at utility bills in isolation but that generates a lot of false positives: people might just like to keep their house cold or warm (depending on the climate).
But once you correlate house size (via the property appraiser's website, public records) with house temperate (which the NSA gets from Google and supplies to the DEA) and electricity usage (utility companies roll right over for these requests) it'll be much easier to put together a pool of target-rich "suspects" who need to be "investigated" to generate probable cause.
Just one of the ways the data rich future just might subjugate us all!
...although many high-volume operations that are based inside of residential properties tend to use illegal/'off the grid' (so to speak) electrical connections...
Or you can install a bunch of solar panels and use them to power LEDs without ever connecting them up to the house's on-grid wiring system. That negates the need to permit it all and making that power usage completely invisible.
At least until someone starts correlating satellite photos with solar permits. Then you're back on the radar, and maybe higher up since only people with something to hide have off-grid solar!
That's where the problem lies: the greatest gains should come from features/sensors/products not yet introduced. Of course temperature preference is a very weak data point for privacy, but I can think of a few invasive things a future device could have. I don't know if that's actually possible with a device in that price point, but if a thermostat could know who is in a room, there's a lot of good/evil that could be done with that data.