Check out this link to see how far Google has come with their ability to track people's every move. They are even taking barometric pressure readings at every location one goes throughout the day!
And yes, they can access your camera and microphone from certain sites you visit. In many cases, the site default is to enable one's microphone and camera, unless the site is instructed not to do so.
For those out there who still care about their privacy, be advised.
I have never, and would never sign up for anything Google.