Will zero out all selected files in Finder.app. Use with caution.

FileEraser.applescript

set iconFile to POSIX file "/System/Library/CoreServices/Finder.app/Contents/Resources/Finder.icns/"

tell application "Finder"
	
	set theFiles to get selection
	set theCount to count every item of theFiles
	if theCount is 0 then
		display alert "No files are currently selected." as warning
		return
	end if
	if theCount is 1 then
		set theCount to "1 file"
	else
		set theCount to (theCount & " files") as text
	end if
	display dialog theCount & " will be erased. Are you sure you want to erase them?" with title "File Eraser 1.0" with icon iconFile
	repeat with f in theFiles
		set f to f as alias
		set f to POSIX path of f
		do shell script "cat /dev/null > \"" & f & "\""
	end repeat
	
	
end tell