The Americans have been doing it for a few years now. Edward Snowden gave up a normal life in order to provide concrete evidence of this fact.
The American government, yes, but a private corporation doesn't have quite the same resources and manpower, not even Amazon.
Right, and the American government stores the data Amazon collects, or they face hefty fees that would put even Amazon out of business. Just look at what happened with Yahoo, who tried to resist.
I'm pretty sure that's not how that works. The government has to ask for it, and they can't ask for what Amazon doesn't have. I'm pretty sure it's more lucrative to put their massive storage capacity to use renting to customers than it is to hold huge amounts of data on the off chance the government might ask for a bunch of information loosely tied to an Amazon account and full of garbled speech collected against the consumer's will to the point where it might not even be admissable in court.
They don't have to ask. You might remember that the Americans government are the ones who developed the internet. All, and I do mean all, electronically sent data is filtered and stored. Yahoo was fined something in the neighborhood of USD$400,000/day until they gave access to their users emails. It's not about taking it to court, it's about data being valuable. You can think of their goal as the creation of a manifest for each and every crew member aboard spaceship Earth.