The best search engine there is, I love how you can easily use the map off of Google to fine where people live for local pick up off of eBay and when I'm lookin for images not websites Google makes that easy to AND THAT MAKES GOOGLE SO COOL.
Google tracks all your movements, when you login into sites, most of them use scripts off google that track everytime you load the page, login, most the sites you visit, when you search something sometimes the site puts a cookie on your computer without even visiting the website, just by looking it up on google. If you don't believe me, clear all your cookies, goto tools and have it prompt you on all the cookies and you'll see.
While Google is in fact a tremendous achievement in internet searching, it's strength is a double edged sword. You can find ANYTHING even if you're a child and shouldn't be looking for everything. While it's not Googles responsibility to police what its' users do, it is none the less dangerous for children who want to find things adults only should be looking for.