I am using Ubuntu 18.04 and I want also to allow to use my PC my brother.
It would not be a problem if it had a guest account but since 18.04 has no guest account I am wondering what data is accesable through a normal user account.
Would it be possible for my brother to change something in the system? Can he access WLAN password or similar data?
I would like to „trust my PC“ after he has used it.