Ask HN: How do you combat monopolies created by network effects?

With the recent discussion over the pros/cons of net neutrality, I've seen more than a few posts talk about the fact that companies such as Netflix/Facebook/Google/Amazon don't necessarily need preferred access from ISPs/telcos to maintain a monopoly. Instead, the posts assert that network effects are responsible for the monopoly -- the value of the service comes from the fact that your friends/family/acquaintances also use the service, and hence you will too.

To my understanding, in a traditional monopoly, such as Standard Oil, the way to break-up the monopoly is to break the company itself into smaller chunks that newcomers can more easily compete with. But how would that work for a Netflix/Facebook/Google/Amazon? If the network effects are that strong, what's the equivalent "chunking" action?

I'm assuming monopolies are bad in general and would rather not get into that discussion. My question is how to break up a monopoly that exists not from price fixing/vertical integration but rather from network effects.