The AT&T split had nothing to do with monopoly regulation (as opposed to the Bell breakup in 1982), other than the fact that Wall Street wasn't rewarding regulated operating companies with dot-com valuations. AT&T wanted to sell hardware to other telcos and dot-coms, so spun off Lucent, which had no idea what it wanted to do with P9/Inferno (which was a fantastic piece of kit!) other than embed it into a couple of network products. Lucent bet heavily on unstable CLECs like Worldcom, generated a couple of headline-creating network crashes, and then failed to capitalize on their pole position in optical long-haul (to be fair, they also bet heavily on a very unstable Global Crossing for that). There's a lot of mismanagement and failures that can be ascribed to Lucent leadership without government or regulatory intervention being involved.
