Hi,
The snake game at https://www.spark.co.nz/snake uses Facebook login and Firebase. With a small amount of code executed in the console you can extract the users table which includes the email, first/last name and profile picture of everyone who has played the game and signed in with Facebook. I presume the intention was that the users table would power the highscore board at the end of the game but having everyone's details public facing isn't great.