Google, youtube, google maps, google earth, the whole android market and the list goes on and on.
I think that's enough power.
Mostly all smartphones use google maps as gps.
All of which are utterly replaceable by any random site. The android market is their thing and guess what it's the last straw and that's why they are defending it so zealously.
Not true. Maps and Earth have big contracts with mapping and satellite providers. There is a high barrier to entry. There is also large brand recognition, and a lot of users and businesses use GMaps to store and share their data, so switching will be a pain (networking effects). Mapquest, Yahoo Maps, and Bing maps already exist, yet no one uses them.
Same for Google's Gmail/Calendar/Docs/Contacts platforms. Google is pushing hard to have their Google Apps suite replace Microsoft's Exchange service in businesses. One you are locked into a suite like that, it's very very difficult to migrate all of your data and server configurations to something else. Aside from MS Exchange, which is very pricey and cumbersome, there aren't really any competing alternatives to the Google Apps suite (which is free for up to 10 users).
I'll grant you the search engine though. There's whispers going around that most of Google's revenue comes from people clicking on things after searching for products, and more and more people are starting to search for products directly on Amazon.com's site instead. If enough people switch from Google to Amazon, and just use Google for non-shopping searches, that will very likely be a problem, though not one Google can't overcome.
