This is why I sign up with a different email address for every site. You need your own domain to do that properly, but Gmail users can use (for example) "email+

This is why I sign up with a different email address for every site. You need your own domain to do that properly, but Gmail users can use (for example) "email+hackernews@gmail.com" to end up with a unique address. Of course it would be simple to get your real address out of that, but I doubt anyone but a spear phisher would bother.