In both cases, the 's does not indicate plurality. It is a contraction of "He has been robbed." "Maine has just had its data stolen." In the second case, depen

In both cases, the 's does not indicate plurality. It is a contraction of "He has been robbed." "Maine has just had its data stolen." In the second case, depending on your dialect, you could remove either 'has' or 'just', but not both. In the first case, you can't substitute 'has' with 'just', but you can use both. That's because "(has|just) had" is an idiomatic expression with different rules than "has (just) been".