Thoughts on infrastructure and monopolisation

This train of thought took me places I didn't like for it to go. I was just going to post this one-liner:

YouTube is taking over the internet. Eek! It's already taking over my life!

And then I got to thinking:

On the one hand, it's a good thing that people are sharing data (besides the fact that it's uncomfortably addictive), but my hands get clammy when traffic and data start to accumulate in single sites. Google, for instance. The idea of there only being a single search engine, like, FOREVER, is scary to me. Or Amazon, for all intents and purposes the only major bookseller, eBay, for all intents and purposes the only online auction house, etc. Particularly since these are all openly traded companies focused primarily on the bottom-line (and thus, inevitably, will have to compromise their now-cemented position as essential parts of the infrastructure of the entire world's information exchange, in favour of making a quick buck to preserve their market standing).

Scary, scary thought: has Google gotten so big that it should be nationalised (or better yet: supernationalised, with the UN as the controlling agent, say?), with a smaller undergrowth of privately owned search engines, each with its own spiel?