Like a scientist working at a radio telescope or the LHC who wants to send 300 TB of data to other scientists to do data mining. They don't e-mail, they burn tens of thousands of DVDs and physically mail them.
And you're not a Pro either. Otherwise you'd know they don't e-mail 300 TB of data either. They don't even send it anywhere, it just sits there in their storage array and gets accessed through the SAN by the different machines that require access to the datasets.
You do understand that e-mailing 300 TB would be a nightmare right ?
Look, Pro users are users that use their computers for their professions (hence the Pro in Profession). Mine happens to require me to use Terminal.app almost exclusively and I can get away with the MBA for it. Pro in the computer name has nothing to do with the use of the computer, end of story.