Try not to create monopoly this large and wait for market to sort this out. There should be like 7 amazons, 7 Facebook and such.
The reason there are now 15 exchanges and not 1 is because the SEC structures the market to incentivize "on the merits" competition and discourage "destroy mode" competition.
In sports we don't tolerate players intentionally injuring the other side, so I'm not sure why we tolerate it in business.
Mergers and Acquisitions have been responsible for the loss of countless services & products. Services & Products that were even profitable, and had a loyal and growing customer base, and a long road ahead of them.
You decrease monopoly problems in one sense, but now the "SEC" and it's quasi-subsidiary entities (NASDAQ, NYSE) have become their own sort of trust. You can even include LSX and other major worldwide markets. International trade deals have brought regulatory regimes close to each other in order to maintain liquidity between markets.
If you did this to the car industry, it would probably make cars worse. It's not obvious what a "worse car" means in the context of a stock exchange or ad marketplace, and dubious that "worse" means worse for us, so a regulator is not out of the question.
That said, I'd rather have fewer or no multi-trillion dollar trusts than a regulated trust.
Anyway, a social media regulator is problematic for other reasons.
IMO the EU & US should just find some courage and act on the findings of their own courts. The marketplaces in particular have already been found (in court) to be operating monopolistically. Split them off. Make adwords separate from Google. Amazon marketplace is trickier, because it is a "real stuff" business... but the same logic applies.
Banks are networked and all speak SWIFT.
Stock exchanges are networked and all speak FIX.
Tier-1 ISPs are networked and all speak IP.
Why can't we make that happen for information infrastructure of a certain size and importance?
The question of America's apparent desire for official censorship is orthogonal to the question of monopoly. And even if it wasn't, people would be a lot more likely to get their preferred brand of censorship from whichever 1/7th Facebook they chose to use.
Things have loosened up quite a bit but the US is behind other countries in allowing advanced lighting technology on cars: https://www.autoblog.com/2018/03/13/why-we-cant-have-better-... "This is because it doesn't adhere to the inflexible and archaic 50-year-old Federal Motor Vehicle Safety Standards (FMVSS) that require all vehicles to have headlights capable of only switching from high to low beams and not blend the two together, which also rules out MB's Digital Light tech."
Breadth is very valuable to and ad business. Targeting makes it moreso.
If you had 100% of facebook's business in Des Moines, IA, you would be raking in the cash. Good luck getting it.
This is the split (most valuable markets kept whole) that would be least detrimental to value, but also least beneficial in monopoly busting terms.