Western Union acquired TWX from AT&T. (A bankrupt Western Union sold both to AT&T in 1990.) AT&T's view of its voice telephone monopoly, which was generally backed up by the FCC and state utility regulators alike, would have been humorous were it not tragic. The mere concept of "foreign attachment" was interpreted SO broadly that even plastic telephone book covers were technically forbidden. Passive attachments such as headset shoulder rests, while not uncom- mon, were technically in violation of the rules. And thus the FCC ruled for AT&T against allowing the attachment of the Hushaphone-a plastic and metal cup that slipped over the mouthpiece to keep out background noise-to a telephone. But in 1956, the makers of the Hushaphone secured a court ruling that permitted their device to be attached. The basis of the decision was that the Hushaphone was "privately beneficial" without being "publicly detrimental." That was to become the new standard. The next major opening occurred in 1959, when the FCC's Above 890 Megacycles decision reversed the course it had adopted a decade earlier and broadly authorized the construction of private microwave radio systems. A com- pany with sufficient need for bandwidth could now self-provision it for its own use. AT&T then engaged in a competitive response, something that it had not regularly had to do for decades. It introduced a new tariff called TELPAK, by which large numbers of private line circuits within a single company's network could be priced as if they were built along a dedicated microwave route. (The circuits themselves were installed as before; the TELPAK customer, however, could create a fictitious route map of high-bandwidth pipes, from 12 to 240 voice-equivalent channels apiece, among it sites. TELPAK pricing was based on the resulting imaginary pipe mileage and the number of channel terminations along the way.) TELPAK successfully discouraged some actual competition, but it was withdrawn in the 1970s when the FCC overturned the general prohibi- tion on sharing and 