Chairy, from the Pee Wee Herman Show, was a female and very social. (She was a hugger.) Is Facebook most like Chairy?
The Lincoln Memorial, the most visited chair in the world (nearly 4 million per year). 175 million log into Facebook every day.
The Gold Hand Chair, by Mexican artist Pedro Friedeberg; gold leaf over mahogany. Expensive piece. I could see Zuck sitting in this.
The Egg Chair, designed by Arne Jacobsen in 1958, is considered the most famous chair in history. I can’t connect it at all to Facebook, though.
The Obama chair. Is that chair up for sale? Got to be worth something. Facebook could buy it, and put it in their lobby. Shared chair anthropomorphization.
Judas Cradle, a medieval torture chair. The victim would be placed in the waist harness above the pyramid-shaped seat, with the point inserted into their anus or vagina, then he/she was very slowly lowered by ropes. The subject is tortured by intense pressure and stretching of the orifice, eventually succumbing to tears in muscle tissue that could turn septic and kill from infection, or simply being impaled (Wikipedia). This is the winner, I believe.