He would not do that. If people do not wish to be contacted outside of HN they leave their contact information out of the profile. I personally like that I have the option and to keep conversations here. If something was urgent I can create a throw-away email and temporarily list it in my profile, then remove it.

I would suggest that if people opt to share contact info in their profile, they should use a canary address that can be discarded without causing grief as there are some unhinged lurkers. I see them planning raids on this site from other sites from time to time.