I found this article pretty funny, but not in the way intended.
Here is a tip for managers (new and experienced out there): If you can't tell by their work product if your people are working or not, then you have a much bigger problem than what they are doing on their computer when you aren't looking.
My experience as a new manager was pretty chaotic. I knew it was my job to lead my team to get something done but between telling them to get something done, and it being done, how could I know that they were working on it? It drove me nuts for a while so I asked a friend who had been a manager for while what they did and the answer surprised me in its simplicity, it was "How much time do you give people to do something, and did they do it?"
The secret was having something that was unambiguously measurable as "done" and establishing that expectation at the beginning. These days I'll say to the team "When we are done, these things will be true ..." and list off the set of things we can say are true to indicate completion. I'll also note them in my notebook so that I can track them over time.
The whole team knows what the exit criteria are so everyone knows if we're done or not. Once you get to know your team better you can add incentive things, so that conversation would sound more like, "The minimum we have to do to insure this is done are x, y, and z. If we can also do p, q, or r it will have this additional positive effect."
It also means I can go to a team member at a 1:1 and say, "Ok, I'd like you to take x, what needs to be true for you to be able to say that x is true?" Which encourages them to break up the problem into smaller bits.
If you have weekly 1:1s with people then you can check in on the status of their smaller bits, toward making the larger bits true. You always know who is doing work and who is under performing or needs help.
For more service type teams (like IT or SRE) you measure things like "our backlog has not grown over the last 30 days" or "the median time to resolve tickets is less than 24 hrs" etc. The key is you can measure it, and the measurement is not subjective.
Managers who need "spyware" to figure out if there folks are working or not need to be replaced with managers who know how to manage.