itigated. A multiyear debate began on the subject. AT&T argued that while MTS rates were above cost, its monopoly profits were necessary to cross-subsidize affordable local telephone service. In 1978, a court's ruling [19] held that since the FCC had not explicitly prohibited MCI from providing switched service, it could not do SO retroactively. The barn door was open and the horse was far gone. SPCC, it should be noted, had its own answer to Execunet. Before the 1978 court ruling officially recognized switched voice competition, it rolled out The Rebirth of Competition a service called SpeedFAX, ostensibly aimed at carrying facsimile. Its basic price unit was the page, not the minute, but it merely approximated pages using the then-standard Group II fax speed of four minutes per page. And of course it did work perfectly well for voice, a detail customers figured out for themselves[20]. Sharing and Resale Had Profound Implications for the Future Historically, most telecommunications services had been reserved for the exclu- sive use of their own subscribers. There were explicit tariff provisions against sharing or resale of most services. This prevented companies from sharing a leased line, which might not be affordable by either one alone, or from setting up shared private networks out of leased lines. It also prevented companies from sharing WATS lines, which had provided an option, but a costly one, for unme- tered long distance calling. From AT&T's perspective, WATS was a bet on aver- ages: A given company would subscribe to WATS if it thought that its usage was high enough to justify it, but the average use was not SO high as to become unprofitable. In 1976, the FCC ruled that private line facilities could be shared or resold [21]. As noted earlier, this led to the demise of TELPAK, since TELPAK's eco- nomics were based on averages; if a company-say, MCI-could purchase cir- cuits at TELPAK rates and resell them, then average TELPAK utilization would rise substantially and AT&T would, in effect, become its ow