That's kind of a poor example, because they kind of did that 2 days ago already:
https://bitcoincore.org/en/2016/02/26/zero-knowledge-contingent-payments-announcement/
A better example would be Company A that has to hand over all their transactions (expenditures, income/revenue, and perhaps balances of certain accounts) to an auditing firm (or the IRS) for a certain fiscal year.
Note: I know the viewkey only shows incoming transactions, but it is possible to show outgoing transactions (and thus balance) as well. In other words, the protocol allows this. It's a bit more different than we initially thought to the extent that it's not simply "give them a key and tell them to scan".
My understanding was that this allowed someone to buy information with Bitcoin without trusting someone else, but how could it be used to enable private contracts? What other unique structures and apps can we imagine that are only enabled via a viewkey (so that zerocoin cannot host such things). Let's think outside of legal compliance.
