I have these two regex expressions being used to block all of MS's domains:
(^|\.)www\.microsoft\.com$
(^|\.)microsoft\.com$
I've done the same thing for things like msn.com, live.com, windowsupdate.com. And anything Apple. Etc. And I have blocked all social media domains with blocklists tailored specifically for that. Except for things like YouTube. If it were only me, since I deGoogled my devices and use Proton Mail, I would just block most of Google's domains and just allow googlevideo (and other Google domains needed to make a site function); it's all I need as I use Invidious anyways.
No one in the household uses Windows or Apple products; we all use Linux. The only one who uses Windows is my stubborn brother who loves being spied on (and calls me paranoid; at least I am the one with more control). But this shouldn't be an issue for him as he constantly uses a VPN to bypass the Pihole. So, I don't have to see his horrendous 'phone home' traffic when he uses Windows.
Good idea? Or bad idea?