I saw this http://news.cnet.com/8301-1009_3-10021715-83.html?tag=nl.e757 on CNET. I have fixed up a short macro to run upon quitting KM to alert me if anything I do not wish is in my clipboard. I will share it just in case anyone else is concerned about this new threat.

KillClip.kmm

#  K-Meleon Macros (http://kmeleon.sourceforge.net/wiki/index.php?id=MacroLanguage)
#
# ---------- KillClip.kmm
# ---------- K-Meleon Macro Language - check clipboard on exit ---------------
#
# Dependencies		: main.kmm
# Resources		: KillClip.js
# Preferences		: -
# Version		: 0.8   2008-08-25
# --------------------------------------------------------------------------------

_KillClip_ExitRun {
	$_KillClip_Check = confirm( getclipboard() , "Erase from Clipboard" , YESNO , QUESTION );
	$_KillClip_Check == "YES" ? &_KillClip_Erase_Check : 0 ;
	}
	
_KillClip_Erase_Check {
	setclipboard("Erased") ;
	$_KillClip_Extra_Check = getclipboard() ;
	$_KillClip_Extra_Check == "Erased" ? 0 : alert( "This is still in your clipboard! \n\n" .  getclipboard() , "Security Alert", EXCLAIM ); 
}	

$OnQuit=$OnQuit."_KillClip_ExitRun;";
$macroModules=$macroModules."KillClip;";