Is this something you would like to see in the documentation?
Here are some details on this, let me know if this is what you were looking for.
When you add an account to access a service like Facebook or Dropbox, FlickStackr launches the corresponding service logon inside FlickStackr. The authentication is managed by the service (FlickStackr does not capture, neither stores ids or passwords.) Once the service has successfully done the authentication it sends back to FlickStackr an access token. This token is what allows FlickStackr to have access to your photos. The access token generated by the services are specific to FlickStackr (no other apps can use it to access your photos). If needed, for example your device is stolen, you can invalidate the access token by going to the settings in Dropbox or Facebook. (For example in Dropbox you go to Your account>Settings>My Apps) When you invalidate the acces token, FlickStackr can no longer access your photos even if the account is still listed in the accounts screen, the only way to get access is by adding the account again in FlickStackr