i.e. Sell an equivalent item at a loss for an extended period of time to force a competitor / retailer out of business? Opening up a physical bookstore after essentially crushing that market felt like a "finger" to ex-businesses to me.
I think a lot of people are mad at Amazon for various things; undercutting mom-and-pop businesses in niche markets, paying people to deliver packages almost for free, busting warehouse unions, counterfeit items, etc. The solution is to not fund Amazon. Move your servers elsewhere. Shop at Target. Ask your representatives to make stronger labor laws.
But all in all, I don't think it's intrinsically wrong to start selling an internal tool and then end up making a lot of money from it. If Amazon weren't dominating online retail, someone else would be. Nobody wants to go to a store. It's boring and there isn't a very good selection. That is not the fault of cloud computing.
If they actually were selling products at a loss to put competitors out of business, that would be considered predatory pricing. Imagine Apple using their iPhone profits to sell MacBooks for $200 - it would distort the market and eliminate competition. It might be good for consumers in the short run, but much worse when they were the only game left in town.
https://slate.com/technology/2013/10/amazon-book-how-jeff-be...
Lawmakers don't do things when one person asks, they need significant public pressure. Publicly showing displeasure with how a company operates is usually the first step for that.