Exchange Control Panel - not only Control Panel after all

When the user goes to Options/Change password in OWA (Exchange 2010), user gets redirected to https://yourmailserver.yourdomain.com/ecp...  Therefore 'ecp' is not for working as 'control panel' only.  (You have to make sure ecp is available from outside access if you configure OWA access through TMG or another reverse proxy device)