Joe Rossignol at MacRumors:
A number of iTunes Connect developers have turned to Twitter and tipped us off about an ongoing issue where users are being shown someone else’s session after attempting to login into their own account. MacRumors has been able to duplicate this issue, which appears to be widespread and has been going on since at least 8 AM Pacific.
Thankfully, developers are getting “unable to process request” errors and are then redirected to their own account if any action is requested while logged into to the incorrect account.