Chimpsky requires you to create a user account in order to let you return to and work with your saved data at a later time. The data you provide as your credentials are not shared with anyone. Your email, if provided, is only used for password reminders to yourself. Likewise, your data files are only visible to you but not to any other user.
Notice, however, that chimpsky does not use secure connections (https), so all network traffic will travel in the clear. So, don't use your most precious passwords, and don't trust chimpsky with any information that you would not entrust to, say, an email communication.