You have to provide your email to sign up for HN, however, it is not publicly visible. If YCombinator had to pay $10,000 for leaking a user email, this site isn't going to exist since it's not their core business and represents a huge liability.

It's also disproportionate. If my email is leaked in the context of receiving treatment for a stigmatized disease, that's a lot worse than an MMORPG leaking my real name.

Maybe some penalty is necessary but $10k or above per user is disproportionate for the vast majority of people. A $50/person penalty with gradations for sensitivity of the information is going to work better in practice. If leaking an SSN is more expensive than an email or site-specific ID, corporations might stop using SSNs to identify people to reduce their exposure