If any and/or all of those are included in one’s contract, then yeah, they can enforce the bejeesus out of them.
That’s how contracts work.
Short of requiring one to actually commit a felony or misdemeanor, as long as one’s signed off on it, they’re well within their rights to enforce it with as heinous a set of penalties as they wish, since one has, that’s right, signed off on those too.
And, as you note, in most cases, the companies enforcing the most egregious of these limitations are often the biggest, most famous ones that everyone wants to work for.
I meself did 3 years at oneoftheworldslargestechcompanies.com , and there was practically no limit to how deep they’d 
with one and one’s livelihood.
These included basic rules like, and I’m not making this up, hours and compensation being based on 2-hour increments, so if one swiped in more than 5 minutes late, BAM! one is docked 2 hours’ pay. Similarly, if one needed to leave early, even just 10 or 15 minutes, BAM! there goes another 2 hours’ pay.
They literally, blatantly contravened labour standards and, if challenged, would pretty much shrug and say, you don’t like it, then quit.
And I promise you, investigation and even punitive action on the part of the CLA were nothing to them.
The first time that I received less than my expected monthly pay, based on HR misinterpreting my performance and docking me accordingly, I went to my immediate supervisor, who, and I’m not kidding, said “If you want to go up against HR, go ahead, but you’re on your own, I want no part of it. Oh, and if you DO, I strongly suggest that you secure another position elsewhere first.”
Worst 3 years of my life.