> Can you name one sustained US monopoly that has existed without government assistance?

The oil and rail companies of the gilded age. It was government regulation (the Sherman Act[1]) that helped put a stop to monopolies. If you read up on Rockefeller, JP Morgan, Stanford and pretty much any robber baron, you'd see that they were in the business of constant consolidation. True, at many points they were aided by local government, but that's because local government wasn't regulated either.

> Uber might transfer risk to workers but without uber these workers wouldn't even have jobs...

Maybe and maybe not, but that doesn't justify exploitation. Think of an island where the people are starving, and some industrialist moves his business there and has the islanders build iPhones for two slices of bread per day. Both the islanders and the industrialist benefit from the transaction, but the transaction is still exploitative, as the industrialist uses the threat of death by hunger to get an unfair deal.

> Same thing is happening with Telsa. Whenever a transformative company enters an industry, the existing players lobby government for regulation and/or to enforce the regulation already in place. ..

I'm not saying that government regulation is always used for good, or that it's even used for good most of the time. I am saying that society is on the whole better with regulation than without it, because (at least in the US) the population was being massively exploited during the gilded age and called on the government for help, and I think pretty much everyone agrees that America is much better for it, even if growth has slowed.

> Uber has ample competition so I wouldn’t say they exactly wield power.

My original comment may have been confusing, but Uber was mentioned simply as an exploitative company (which might some day become powerful) -- not a currently powerful one, unlike Google and Amazon, which are already too powerful.

> This is ridiculous. Government’s role is to serve the people. Government knows better than the people? The government needs to protect citizens from themselves?

Democracies protect people from themselves even when it comes to the democratic process itself. Most democracies prevent people from voting in a dictator, even if the people really want it. They install checks and balances to prevent an accumulation of power even if the people want it. And it's not about knowing better, but averting disaster by slowing down the growth of potential "cancerous tumors". The government doesn't (and can't) always decide what's "good" and what's "bad". All it can do is prevent individuals or organizations from growing too strong, so that if something bad happens, the damage is limited. This means that some potential positive effects are slowed down as well, but lowering the risk for a disaster is usually worth it.

> How would they determine when an “unelected body” gains too much control over people’s lives?

Just as Teddy Roosevelt did. When the exploitation starts piling up, the media exposes the control, and the people call for change.

> Transactions only occur when both parties think they’ll benefit.

Like I said before, this doesn't mean the transactions are carried out when both sides are free of duress. A surgeon and a homeless person aren't as free when it comes to the choice of, say, buying drugs. The surgeon has a lot to lose if caught, while the homeless doesn't. Performing transactions when one side of the deal has limited choice or limited knowledge is exploitative even if that side benefits, too. In democracies, the weak side will hopefully be educated of the exploitation, and then use their political power to tip the scales more in their favor. The idea is that democracies (though they're far from perfect at that; really far) are able to generate other forms of power to offset that of property.

If the rich are free to exercise their power -- money -- any way they like, the poor should be free to use their power -- their numbers -- to fight back. This is why I think American libertarianism is so hypocritical, as it places limitations only on one side but not the other. If regulation on money is to be completely lifted, than so should regulation on violence. But since many people don't want that, we have democratic institutions that give the poor some power back (though not nearly as much as they would in an anarchy, where they'd be free to use violence, which is why democracy, too, mostly serves the rich).

[1]: http://en.wikipedia.org/wiki/Sherman_Antitrust_Act