[dragonwriter]

> I could see someone suing an SaaS vendor for an action like this, actually.

So? A SaaS vendor that shuts down operations in to avoid complying with a mandate of a court is taking a major risk of losing all its assets to legal action by the government. On top of that, the risk of legal action by dissatisfied customer is a pretty small marginal cost.

> "You cost me $XX in actual costs and $YYY in lost business. Your TOS says nothing about your shutting down because the government asked you to do something you didn't agree with."

You'll probably find that, unless you have specific contract terms relating to expected costs of failure to provide service, expectation damages of the type you describe are barred by the foreseeability prong of the test for expectation damages.