er, no, it was licensed, but available to educational institutions. I remember having to send Bell Labs our university calendar when i wanted to get a copy of LSI-11 Unix circa 1976. What is true is that Ken Thompson visited a number of places over the years, and maybe from time to time he forgot to pick up his Unix install tapes when he left.

Bell Labs/AT&T claimed exclusive ownership of Unix, and the exclusive right to license it, right up to the BSD case in the early 1990s, where it was determined that AT&T had used Berkeley code, and vice versa, to the point where copyright notices were essentially fiction. Berkeley Software Design had to remove a small number of files from their distribution, and then System V and BSD could go their own separate ways.