Maybe what we should prevent is employer keeping months of proof and only bringing it up as inappropriate later, but if the employer uses the camera to tell an employee within 24hrs that he needs to ramp up, it feels ok. Maybe we should impose rules like “24hrs max” and “can’t be used legally, just orally.”
On some level it depends on what 'slacking off' means.
I've had employers where 'slacking off' meant actively doing some %mundane/repetitive/unnecessary% task with every moment of my free time. We were literally pulling the finish off the counters; there was no need to keep dusting them.
I've had software shops where reading integration documentation was 'slacking off'.
An interesting data point; In Germany, MS Office doesn't track how long you have been editing a document. My understanding is this is because the law there more or less says if you pay someone to do a task, you aren't supposed to (i.e. can't) care about how long it took them to actually do it as long as it was done on time.
So I guess that's my problem. There's a very fine line between employers using surveillance to catch 'bad actors' and employers using surveillance as another tool to bully substandard work conditions onto people.
I'm sure they have a legal right to check (in the US), but I really wouldn't want to work for such a company and would immediately start looking for a new job if it happened to me.
Not at all in the paranoid "are you slacking off?!" sense, but just security information like knowing when I've been in a server room, or knowing if my work computer sent traffic to a known botnet C&C. If there's a security or theft incident and they don't know who's been in their building or what their computers are doing, it's pretty much impossible to investigate anything.
I understand that in places like Europe there's a very different culture and workers have a lot of protections from things employers may want to do, but not everyone around the world feels that way. Basic record-keeping of when badge-restricted doors and computers are authenticated to doesn't feel invasive to me in the slightest, even if others may strongly feel it is invasive.
There are many things I would find egregiously invasive, such as a manager inspecting all the websites someone visits to assess how productive they are, or timing people's bathroom breaks, but I just avoid such companies.