We promise to do nothing bad with any personal data we get from anyone. It will certainly not be sold or given to anyone else for any reason.
Any map you make is private. The only way to view a map is to know its ID, which is a part of the URL, and those IDs are random and cannot be guessed by other users unless you share it with them.
We pledge that your maps will never be shared with anyone without your knowledge and permission. The only exception is that Mipui admins might occasionally look at user maps for development and quality assurance purposes.
Despite the above, please avoid storing sensitive information on maps (e.g. credit card information).