Finally. I've been predicting this is exactly what FB would do eventually: ASK for regulation.
Facebook could do all these things in isolation, but generally speaking this could be really bad for long-term revenue. Essentially Facebook is stuck between a rock here; big moves will satisfy their user base, but annoy their large investors. On the other hand, doing nothing will harm users in the long run, but probably they could generate plenty of revenue in the process, so share holders would encourage this. Additionally if Facebook did this on their own, but other platforms are not subject to the same restrictions, they are at a huge competitive disadvantage.
I think this is the key value in broad government rules. Regulation here is both good for users and good for FB (and other platforms) in the long run. They can protect their users without having to explain to investors why they aren't just going straight for profits, because they will be bound by the rules established by regulation.
So in the end, FB should WANT regulation, because it's better for them in the long-run. I'm glad to see Mark appears to have finally realized this.