Any split would be self-enforced. The ban on acquisitions would be the impetus to stay under the market cap. The article specifically notes that the Bell split

Any split would be self-enforced. The ban on acquisitions would be the impetus to stay under the market cap. The article specifically notes that the Bell split was a bad model, as it just created multiple local monopolies. As a shareholder, I don't particularly lose as now I own stock in Google Search + Google Maps + Android (or whatever combo). Or corporations decide they want to stay big... but can no longer defensively acquire prospective competitors. Which seems to cleanly solve the problem of "No one aspires to be the next Apple / Google / Facebook, they simply want to be bought by them." It would depress valuations (as there wouldn't be a reliable acqu-exit), but that might not be such a bad thing either.