We have used industry standard encryption algorithm to encrypt your passwords before storing them to the server, which can only be decrypted using by the encryption key which is not visible to any user of your organization. The only way one can access the passwords are through the force.com, which has another layer of security which user has access to which records which is configurable by you.

This way we have ensured that only authenticated users can access the passwords. But for your safety we highly recommend not to store any credentials which can have any kind of damage financial or otherwise as we will not be liable for any such damage.