By that logic let's monitor their clipboard for email and phone numbers. Let's tell them that they should enable notifications so we verify they're not a robot.

By that logic let's monitor their clipboard for email and phone numbers. Let's tell them that they should enable notifications so we verify they're not a robot. Let's ask them to download a little executable to see if we can find helpful ways to reach them. We'll provide an unsubscribe link, I promise. ... But let's just record they clicked unsubscribe because that means they're engaged. I mean maybe they clicked in error? Let's ask them to confirm. ... But maybe they confirmed because they were confused and didn't understand the great value we provide. We can beat around the bush our way to full-blown scammers all day. Saving emails from a form NOT submitted is bullshit, and you know it. The user never intended to submit.