For most people, it doesn't matter at all if their email address is posted publicly like that. Any email address that someone has used to sign up for services f

For most people, it doesn't matter at all if their email address is posted publicly like that. Any email address that someone has used to sign up for services for years is going to have been leaked anyway. There's very little value to just a plain email address with no password, no context, etc. If you posted your (let's say) Gmail address on HN, the spam level of your inbox wouldn't change. Gmail might work a bit harder filtering out some spam, but it would be lowest-common-denominator stuff that they easily recognize.