It's a class that's allowed to access another class's private members. Obviously Linus doesn't have any, because he codes in C.

It's a user group

I searched the web and found this article: https://en.wikipedia.org/wiki/Friends

It’s a second user account on your machine. Of course, you don’t put them in the sudoers file. 

I actually made three new friends on new years eve completely through mentioning Linux. We were at a party and I had a really bad year last year so I was rusty in the "talking to people" department, the few people I knew there, who are indie games devs that don't use Linux, said something (can't remember exactly what) that made me reply with a Linux joke and those three people moved their chairs closer to me with a "ooooh, a linux nerd, let's fucking go" energy. We went on such a nerd dive that they party host told us that we aren't allowed to talk Linux anymore or we'd have to leave.
We talked a lot more through the night and had to really concentrate to not get thrown out, haha.

Friend here, what's a linux?

Another contributor who doesn't have wildly differing political ideals from your own, I think?

Super popular tv show from the 90s with Jennifer Anniston (from Office Space), Courtney Cox (from Scream) and a bunch of other schmucks that I can't remember.

sudo apt-get install friends

Awesome package! Still figuring out what it does though 🤔