Green’s Dictionary of Slang

(N.Z. prison) to lack a TV in one’s cell (usu. as a punishment) [play on the Pink Floyd’s 1979 album The Wall: thus the inmate has nothing to watch but the cell wall].

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 141/1: watch Pink Floyd v.to be without a television; used esp. by an inmate in the pound or on OPs who has had his television confiscated.