> I can't imagine how in practice we could construct a regulatory regime which would prevent large tech companies from acquiring small start-ups which represent

> I can't imagine how in practice we could construct a regulatory regime which would prevent large tech companies from acquiring small start-ups which represent only a potential competitive threat with little current market share. How about: once you hit a certain market share, you're no longer allowed to acquire businesses that compete with you in some feature category? There could be some processes where a court adjudicates what the feature categories are in each case and whether or not they're the same. There's already some concept about how to do this, since it's not uncommon for a company to be forced to divest a division or two during a merger.