What kind of video is it, and how is it possible that people can get hold of it?
If itÂ´s just personal...donÂ´t let anyone have a copy of it!
(...or, make sure itÂ´s not interesting enough for anyone)
Anyway...as I think has been made clear already, anyone with the right software can deal with any protection you put on it...meaning, theyÂ´ll be able to copy it if they want to. Remember that major movie studios spend millions copy-protecting their movies...and anyone here can break any protection!