A "yechidus" is a private meeting with the Grand Rabbi. The Lubavitcher did this until his health failed.
I heard one Lubavitcher telling another who was about to have a yechidus that he should tell the Rebbe everything that's on his mind, don't hold back, "don't worry the Rebbe already knows everything..." I'm sure it's just mind control
Similarly, the Chabad movement tries to hook up every one with a close friend to whom a person is open about everything.
It's not all in innocence. It's done for the purpose of control.
Once Rabbi Yaakov Goldberg the Rosh Yeshiva of Hadar Hatorah, the seminary for "late starters" in Chabad said something to the effect that if a student was out of line they tell him, "we know who you are, we know who your friends are and if you don't [get in line, we'll lean on them to get you in line]."