Google, FB and Twitter are all de-facto monopolies.
Time to break them apart like they did ALCOA and Ma Bell (and a few others).
The time is now.
I have no intrinsic problem with that sort of natural monopoly - companies who through innovation and foresight create and dominate their segment of the marketplace. When they abuse that power it is appropriate for government to step in, though not necessarily as heavy-handedly as often happens.