Can Watermarking Help Find GPL Violations?

bitkid writes "I recently run across techniques that can be used to watermark program code. While I yet have to see some source code for this to play with, the authors claim that the watermarks can be introduced into the source code and can be found in the compiled executable. My question for the slashdot-crowd is: Do you think free software (GPL or other viral licenses) should be watermarked? This could help to find GPL violations (think Everybuddy or Linksys) or can be used in court someday against the next SCO to prove authorship. What might be the ramifications of this?"