As others have noted, Google owns YouTube. Remember a while back when they changed their privacy policy? This was to allow them to track everything
they can about you across all of their properties and applications. And by the way, that includes any website that displays ads from Google or uses
their scripts for website analytics, everything in your gmail account if you use gmail, etc.
If you want to really get paranoid, remember when Google got in trouble when it was learned that all those Google streetview cars were also
intercepting any wi-fi traffic in an area?
One of the things they were doing was collecting geolocation data for every wireless router and every wi-fi hotspot. And most newer browsers can do
geolocation using HTML5. In many places in the world, this allows any web page you hit that uses geolocation code to know where you are.
This can be done even without GPS, and whether you are on a desktop computer, laptop computer, or cell phone. It uses information about nearby
wireless routers, wi-fi hotspots, and/or cell phone towers and their relative signal strengths to calculate where you are.
The demos I have seen require you to accept sharing your location, but I imagine it is probably possible to avoid that.
Here is a demo from Gazpo (a web design tutorial website):
Gazpo geolocation on Google maps demo
It will prompt you to share your location. If you want to try the demo, it will only work if you do share your location. At least in Firefox, you
can choose to only share it the one time or all the time, I imagine other browsers will have similar choices. I did notice sometimes the demo didn't
work (didn't find me) but if I refreshed the page and did it again it worked.
The demo will show where you are on Google maps and you can zoom in and even choose satellite view. At least where I live it's quite accurate.
Scarily accurate.
If you want to see Google's documentation on their Google maps geolocation API for developers, here it is:
The Google Maps Geolocation API
Probably the best explanation I ever heard of SEO (search engine optimization, for getting a website listed higher in search results) was that you
have to understand what Google wants and how they try to get it.
Google wants to make tons of money from advertising. To do this, they want to as best as possible show you search results for EXACTLY what you are
searching for so they will stay the #1 search engine. And they always want to show you ads that most match what you are searching for or what your
known interests are so their advertisers will pay them lots of money because they make more money with Google ads.
This is the #1 reason they want to know everything about you. It's the same reason stores want to have you get a card for their store to get
discounts, so they and the marketing research companies that analyze the data can profile you and sell you more stuff.
Of course, it's also worth remembering that Google allegedly no longer demands a subpoena when the government requests personal info on someone or
some group...