Clipboard contents is a very sensitive data stream. People copy and paste all sorts of passwords, credit card data, command lines, confidential text etc. I once

Clipboard contents is a very sensitive data stream. People copy and paste all sorts of passwords, credit card data, command lines, confidential text etc. I once found the domain password of a coworker in the clipboard, simply because we were sharing a VNC session; so when I pasted the text data I immediately recognized it as a password. If this can happen accidentally, I think logging this data stream on the long run is equivalent to full compromise and can spread malware or worse in the internal network. An easy active attack I could envision is to listen on the remote clipboard for something that looks like a long Unix or Windows command line, which the remote user lifted from a tutorial or some such. Malware would immediately trigger a sync event to modify the remote clipboard and insert a loader for itself, obfuscated somewhere within that command line. So from the time you copy to the time you paste and press enter, the machine is rooted, unless you carefully review that command line before execution.