I sometimes imagine local laws/contracts with a provision like: "This system may not be operated if there is no state law that makes it a class X felony to violate someone's privacy in any of the Y conditions."

In other words, the "we're trustworthy we'd never do that" folks ought to be perfectly fine with harsh criminal penalties for misuse they're already promising would never happen.

This would also create an incentive for these companies to lobby for the creation/continuation of such a law at the state level, as a way to unlock (or retain) their ability to do businesses in the localities.