Why would you need that?
At the end of the day, the items in your main character just got MOVED around the other alts in the account, but it is STILL in your account.
Unless you knew, untradeable items that got put into the stash does not make it tradeable, so your items is still in your account.
As of what the RED CHAT always says, DO NOT SHARE YOUR ACCOUNT INFO WITH ANYONE ELSE.
If that is not clear enough, it meant do not give away your ID and Password to another person.