Maybe some ISP's like this. The last time I tried to find a free DNS is two years ago when the ISP DNS was down. I like the ip they choose, easy to remember.
Maybe DNS is the first place that browsing statistic can be collected.
"To try it out: Configure your network settings to use the IP addresses 18.104.22.168 and 22.214.171.124 as your DNS servers or Read our configuration instructions."
- Google Public DNS (view on Google Sidewiki)