GoogleFoobar
The Google foobar page is not accessible to everyone. Google has a list of what the user goes searching for and if it finds it relevant to programming, it gives the user an opportunity to participate in the foo bar challenge. The message reads like this.
You are speaking our language. Up for a challenge!
I accepted and SignedIn with the id and landed on the page
Upon completing the Level 2 you get a referal link(one time use only) to refer your friend.