Which says:
"Linus wasn't inventing a new operating system; he was deliberately
trying to create a Unix-like OS. In that sense at least, this is 'theft'."

I don't see how it is "theft" to write, from scratch, a piece of
software that implements standard published interfaces such as the Unix
standards (POSIX).

"The Open Group would like to make it clear that SCO holds the rights
only to the operating system source code originally licensed by AT&T and
does not own the UNIX trademark itself or definition of what a UNIX
system is." http://www.opengroup.org

AIUI unless someone can point to copyright, trademark or patent
infringements then there is no "theft".

Just my GBP 0.02 worth.