Someone with telephone industry experience sent this bit of information anonymously:

Here's another highly relevant piece of case law to look up for the fight
against 1116: The Carterfone (correct spelling) case, I think it was
1967 or '68, and it started in Texas.

Carterfone manufactured inductively-coupled devices that would allow you
to connect your (rented Bell) telephone to your company's two-way radio
system (e.g. truck dispatching system etc.). Bell took action against
them for violating the "foreign attachments" tariffs against non-Bell
equipment, even though the device was inductively and acoustically coupled
(did not make a metallic connection to the actual telephone line).

Carterfone went to court on this and won.

The outcome set the stage for *everything that followed* in the
deregulation of telephony, starting with "station equipment" (subscribers'
apparatus, on the subscriber's premises). It led directly to the
"interconnect industry" in a 1970s precursor to the dotcom boom, and was
arguably responsible for the opening up of data communications that would
ultimately spawn BBSs and lay the foundation for the civilian Internet.

See also:

http://www.patobannon.com/iss08-22.html


http://yarchive.net/phone/carterfone.html

(do a general web search under "Carterfone" and there's plenty more where
these came from)