So you filled out a form with your personal data and were about to press the submit button to send it to them, but you don't consent to them knowing that data about you?
It seems the checkbox had its intended effect of serving as a double-check gate about whether you really want them to know that information.
Strange as it might seem, I just wanted to download a spec, not be added to any database. regardless of their uses. Is that too much to ask ?
Any anyway, my biggest gripe was the phrasing, don't say it as if I have a choice.