How do these things work with work from home? Activity at one's home or anywhere outside the offices is private, even if it's work-related. Could remote employees block such requests on the ground of personal privacy?
What are you talking about? Your employer shouldn't have access to your private activities in the first place. Just because you are out of office and you send a company email doesn't make it private.
Activity on a BYOD device can be subject to the legal discovery process. Always use separate home and work devices.
It's your work device and can be investigated when pursuing against your employer, activity in your work computer in your home is part of your work and your employer's IP so there's nothing about personal privacy here. Use your own devices for personal use...