If you feel like you need these monitoring tools as a leader or manager perhaps take a long hard look in the mirror in regards to your own management abilities. I know what employees are doing their job and doing it well by the timeliness and quality of their deliverables and the amount of imitative they are taking. If an employee is not meeting expectations have a conversation with that employee and figure out why. The only thing monitoring software does is make everyone feel disrespected.
To be clear, a small moonlighting gig that's in keeping with business rules is fine. A second full-time job is almost certainly not.
If I am laid off (company doesn't give a shit about me), will you give me part of your salary? No right? So why the f should I care if my actions (assuming they are legal) affect you? 2 salaries? Yay, I will get to retirement in half (or less even) time. Have a problem? Well change companies or do it the same. If your company punishes everyone for a couple individual actions, they don't know how to manage people or even who is working two jobs, just a suspicion. Change jobs, but let the people that can and prefer to work 2/3 jobs, finally had an opportunity to get ahead alone. It is your problem, not theirs
It's about integrity, something many people lack here in America today. And I very much doubt they are producing enough. They are likely working 10 hours a week per job. Being both an employee and a business owner that has employees, integrity is critical to any type business relationship. It may not seem like it, but trust me, it is paramount.
[1] unless your employment agreement also specifices some sort of exclusivity.
I'm not agreeing or disagreeing with that position personally, just exposing it
Perhaps not the wisest opinion, but so it goes.
I'm the opposite - I learn best by studying and tinkering (what with having 6 years of higher education steering me that way and all...). Nothing kills that off faster than having somebody looking over your shoulder saying, "why are you looking at the HTTP specification, somebody else already knows how that works".