[bluekitten]

From the perspective of web users, there is choice(even if heavily skewed by default search in browsers). But from the perspective of web sites/web companies/web devs/web advertisers, there is very less choice and bordering a monopoly, as this example illustrates. Even worse if you're someone like MapQuest, a shopping site, or Yahoo Finance, since most people tend to search locations on search engines/browser and are quickly steered to their equivalent competitors from the search engine company. Anyway, usually antitrust regulations are about market power and influence, for example see DoJ vs. Apple over eBooks, even though iOS never even had majority share, forget about a monopoly.

[angryasian]

The U.S. accused Apple Inc. and five of the nation's largest publishers Wednesday of conspiring to raise e-book prices. I don't even see how thats relevant to how Google does business within their own ad products. Who exactly is Google colluding with to suppress or hurt competition ?

Companies will do business where the users are. The minute there is a better product or users abandon google, those same people you listed will leave as well. So maybe we should go after Facebook for destroying MySpace as well ? The entire argument is based on the fact that Google offers a superior product and should punish them for this.