Earlier quoted context omitted.
Installing an extension to monitor employee use of a company computer is legal and generally accepted behavior. If the Google calendar is for a personal gmail account, then accessing the calendar details server side is a huge privacy breach.
It’s not legal if employers specifically use it to disrupt employees’ attempts to organize. The NLRA specifically grants employees the right to organize and it prohibits employers from monitoring these organizing employees. The fact that Google employees, in this case, may not be considering forming a union at this time is irrelevant. The meetings they are having may prompt them to form one at a later time. Either wa…
Google also has a clause in their employment agreement that says you agree to them putting surveillance software on your devices, company supplied and personal, as a condition of your employment. I asked about that one, got the HR response "Well I suppose you could interpret it that way, but that isn't what we mean." and I said, "Okay, lets change it to say what you mean." and got the "Well we really aren't in a position to change these documents, it would be a mess trying to track a zillion individual agreements." etc etc. That rabbit hole of pushing back and forth leads to "perhaps Google isn't the right place for you." :-)