> I agree to breaking up Facebook. But the message falls flat when the suggestion is to spin off WhatsApp and Instagram into separate companies. This doesn't really do anything.

It does, because Facebook protects its monopoly by making sure it owns its competition. Instagram, WhatsApp, and Snapchat are its competition, and the first to are far larger than the last.

Bell telephone was broken up geographically for technical and infrastructural reasons (too expensive to build duplicative) telephone exchanges, I'd imagine), and I'd argue it was a poor example since it left regional monopolies.