If a family member gets banned for cheating while playing your copy of a game, you will also be banned in that game.
from this terrible idea and its announcement

i dont have much to say here honestly. i mostly listen to albums that are fed to me by youtube. i try to keep people updated to interesting stuff i listen to but often im just rewatching videos. i complain and gush about kirby sometimes (a lot an abnormal amount), especially the mopupu manga. my life is a wreck which is a majority of my posts. i dont recommend following unless you uhhh like my thoughts or love hearing about kirby. im a major btw, not a minor. trans masc, bi, tme, mexican in the usa.
If a family member gets banned for cheating while playing your copy of a game, you will also be banned in that game.
from this terrible idea and its announcement
sibling goes to your most played game and then installs cheats and bans you from the game to troll you
post phrasing suggests the whole program is a terrible idea
the ban thing was also previously existing policy for VAC games, and within the ability of developers to implement individually -- anything else is free ban evasion.
"Yes, adult family members can kick any family member out of the Steam Family" oh this is going to be entertaining