Is that a rhetorical question?
"What happens when users are left to their own devices?" Hmm, let me see.
Virus / malware infections.
Lost data, and no backups.
Open wireless connections.
Users with 30 search toolbars
Everyone logging on with the same username (and password = 'Password1')
Printing all in Hig Def colour (using branded ink jet) so that the spreadsheet looks 'nice'
Marketing decide what software you should use, based upon how funky the presentations are.
Separate folders on the server (for pr0n), everyone else uses the same folder for everything
300Gb mailbox folders (290 Gb of picture attachments of Girls night out, holiday snaps, grandchildren, cars, latest DIY projects)
Different versions of files in different locations
Or am I just being cynical?