When viewing a user page on the full site, moderators (but not SE Employees) see a little "click to show" link in the email address field. Clicking this reveals the user's email address (obviously).
However, on the mobile site, when going to a user's page, their email address is already shown. (Sorry, no screenshot for this.)
I imagine that the reason the email address is hidden by default is to protect the user's privacy; so that moderators see that information only if they decide to contact that user. I feel that users should be afforded the same protection whether the moderator uses the full site or the mobile site.