“In the event that you choose to create an Account and play the Game, we also collect certain information regarding your in-Game performance and/or interactions with other users (e.g., wins / losses, recent champions played, average number of kills / deaths etc.). These statistics are associated with your in-Game Summoner name and are publicly accessible by members of the Riot Games community. In addition, we may share your in-Game statistics with third parties in accordance with the terms and conditions set forth in this Policy. To be clear, no personal information about you, such as your email address, username, IP address, or other sensitive information, will be shared as a part of this process.”
This means that everyone will have access to player stats. They say that people “make awesome stuff” with game data like this, but I have no idea what sort of fantastical things you can do with that. More info on this will surface in the coming months.