I'm not sure what Kevin's workbook looked like, but if you right click on the
excel icon to the left of the File option on the menubar, then select view code
and paste this in:
Option Explicit
Private Sub Workbook_BeforePrint(Cancel As Boolean)
MsgBox "uh, uh, uh!"
Cancel = True
End Sub
It'll stop a few people. But if the user opens the workbook with macros
disabled or just disables events, then this won't work.
And don't forget that you should stop copy|paste (so they don't print from
there) and even alt-prt-screens so they can't get pictures of the screen.
(I think this is a losing battle.)