The Othello Crush data deletion instructions explain how to remove an account and related game information.
When the app is installed, an account is created to run the game. Relevant data is stored in encrypted form and SSL is used for connections.
To delete game data and scores connected through Facebook, remove the app from your Facebook applications list at https://www.facebook.com/settings?tab=applications&ref=settings. Questions can be sent to Zodor Productions.