That's a good fear to have. That's the kind of thing I would set up some monitor...

That's a good fear to have. That's the kind of thing I would set up some monitoring for and then wait to see. You might get a few jerks. But those same jerks might also be the sort of people who would sign up with a bunch of fake emails, so gating on an email address may not be much better than gating on a fresh-issued cookie.

Thanks for listening, and good luck with your project!