First of all, OP can already track other people in the office by observing when they come and go. What's the moral difference between that and checking to see whether they also emit some electronic signal when present?
Second, it's common for workplaces to have cameras and doors with badge access that track this sort of thing already. So it's not like he would be doing anything creepy even if he were the employer.
Irrelevant. It's all about expectations. If people know that they're being tracked in this manner and they're happy with it, then fine. It becomes creepy when they're being tracked by a colleague without them knowing about it. In the same way that hiding a GPS monitoring device on your partners car without them knowing would be creepy.
Hence my question: Do his colleagues know he is doing this?
[edit] I know I am being "tracked" by colleagues when they are physically present and can see me enter the room. I also know I am being tracked by my employer when I use my swipe card to enter the office building. What I assume is not happening is that any of my other colleagues have electronic devices collecting my arrival/departure times for whatever purpose, regardless of their presence.
What if he started hiding microphones in the office? Is that ok? After all, if you say something out loud in the office, people can already use their ears to track it...
OP here. There were five of us and we all knew it was happening because it was a prototype for a client we were pitching. But we collected data from several hundred unique MAC addresses from the surrounding office spaces, including their wireless NAS and Philips HUE lightbulbs.
We never knew the MAC addresses of anybody but ourselves, though with physical surveillance we could have correlated MAC addresses to comings and goings.
Basically I don't feel that this is particularly creepy unless you are applying it to identifying and tracking specific people. For bulk population metrics I have no problem whatsoever, and I have no problem being tracked in this way, but as a data analyst I know that the line between 'fine' and 'invasive' is a single SQL query.
It's kind of like how tracking phone calls metadata for billing is OK, while tracking it for surveillance is not, and the difference is the collector's intention.
> What's the moral difference between that and checking to
> see whether they also emit some electronic signal when
> present?
This is the key question actually, so I'm glad you asked it.
Manually observing someone and making a note costs resources. Which means you won't bother doing it unless you have reasonable cause to. If John in accounts has a reputation for being late and not getting his work done, you might decide to have someone make a note of what time he comes in and leaves.
If it's automated, that cost goes away, and you can just randomly trawl the data and look for anyone; it's become massively asymmetric. Suddenly John in accounts who was 10 minutes late every day but doing a good job gets a call from HR.
This is generally the problem with mass surveillance and putting the data in to easily queried databases: the cost to query and surveil becomes much much less, which removes the need to have reasonable cause -- you can just go for fishing trips and see what you find.
It's not terribly common, but my workplace is a union shop, and electronic monitoring of employee movements is mostly forbidden by contract for most folks.
Second, it's common for workplaces to have cameras and doors with badge access that track this sort of thing already. So it's not like he would be doing anything creepy even if he were the employer.