Yes, as a moderator, we have used access to the email of a user in the Admin area, their Profile page, etc as a way to identify members as spammers, advertisers, etc.
We use it a lot, as it is one of the important keys, along with username patterns that we can use to immediately identify a user as part of a larger group who does nothing more than post frivolous crap. You’d be amazed at how terrible human spammers/advertisers are at trying to conceal themselves.
But they do exist for Moderators…