Well, really, this is no different from how you'd prevent a user from printing an HTML page, or the browser output of a CFM or Perl or PHP script. You can use CSS to hide the body of the page:
<html> <head> <style type=text/css> @media print { .body { display:none } } </style> </head> <body ... > <div class=body> ...sensitive content... </div> </body> </html> |
Of course, just like protecting images, javascript or CSS code, there is always a workaround. In this case, nothing prevents the user from using PrintScreen, or a browser that doesn't obey this style sheet declaration. Obviously it's going to be more trouble than it's worth, depending on the length of the document.