I'd even accept a step during OS initialization, when it could ask something like: "how much do you care about various apps being able to read your clipboard?"

I'd even accept a step during OS initialization, when it could ask something like: "how much do you care about various apps being able to read your clipboard?" 1. I care a lot: I want to be asked every single time whether I approve of my clipboard getting read. 2. I care a moderate amount: ask me the first time an app tries it, then stop asking me for a while. 3. I don't care: let apps do whatever they want. I'll let other people worry about my security. (albeit phrased more diplomatically, of course)