vent box

A person who people go to talk to constantly to complain or ask for advice but never actually gets to speak their own mind or share opinions. They are used as a box to put problems in and never hear a word back from.
They're usually introverted and to shy to speak out, if they're not and they do speak out they'll either be ignored, ridiculed, or outright insulted for doing so.

Stacy: "OMG I CAN'T BELIEVE YOUTUBE REWIND THIS YEAR! OR THESE RACIST POSTS!"
Vent box: "Stacy Youtube is a corporation, and they're basically giving out free money, why is this one video a problem? Also those posts are from black people IN Africa complain-"
Stacy: "OH I GUESS YOU KNOW BETTER HUH!? WHAT A FUCKING JOKE OF A FRIEND. I'M DONE LISTENING TO YOUR RANTING FOR THE DAY JESUS!"