Ignoring the "morality issues" of worrying about "getting caught", any video that has not been released into the public domain can not legally be redistributed by anyone other than the producer of said video.

As for "tracing" video, some video formats... especially MS's own Windows Media formats (WMV, WMA) can include programs that run when the file is launched, and they can conceivably "contact its producer" upon launch. There are a TON of commerical "teaser" videos... mostly from porn sites... that do this, that prompt you to Pay before it will run. You can redistribute these videos as much as you'd like... I'm sure they'd love you for it. But it's also a great way to find yourself on everyones "banned hosts" list in LimeWire.