Even if it were just the emails where they don't already map to a meaningful response...

With N million users, odds are high that at least N thousand of them: are irrational, just need someone to talk to, can't express themselves in writing, think you're their new pen pal, find you attractive (even if they've never seen you) and just want to meet you, etc.

I know that as users and customers we all want to be treated as beautiful and unique snowflakes. But a service of any scale will have many thousands (or more) of users that are just completely batshit crazy.