In these cases, stolen usually means that existing tokens were moved around in some way. In this case, it looks like they hacked a bridge connecting one tokens

In these cases, stolen usually means that existing tokens were moved around in some way. In this case, it looks like they hacked a bridge connecting one tokens protocol to another 'chain' and redirected tokens there - not sure if they were swiping them out of a wallet at rest or redirecting trades people were doing.