We read the firewall logs, I would keep that in mind if I was you.
Oooh, scary. Kinda like a Lois Lerner clone threatening an audit if'n she don't like yur type.
So some user wants to use a Mac and we're supposed to bend over for him...
Yes. Because servicing the technical needs of the business is IT's job, not gatekeeping them. Ain't nothing sacred about MS operating systems. If that user is more productive for the company on a Mac, or Unix or a Univac or an abacus, your job is to make it so, not get pissy over your turf and try to force all users into your mold. The users are the ones making product and money for the company.
Seriously, you sound just like an entrenched DC bureaucrat, writing one-size-shall-fit-all regulations, and throwing insults at anyone who questions your author-i-tay. You seem to have forgotten that the purpose of IT is to service, not dictate.