If logic doesn't work, which it often doesn't, I'd expect the most effective way to be highlighting how it can affect you, or public pressure. Like "did you hear how Facebook tested how it can influence people, and even drive them to suicide?", "did you see that cop who stalked their ex using flock cameras?" Or "you know those smart glasses? Turns out they do spy on people even without permission, but they can also look shit up in real time. Anyone interested in them is a weirdo/pervert."

It's really hard to wrap your mind around a data leak, but one cop being a sick fuck? That you can take in. Get them interested first and then offer solutions.