From their feature list:
"Easy to use : when a video is detected, the download button becomes clickable." - i.e. our plugin sends all URLs to us for analysis, we respond telling the plugin whether to activate the button
"Integrated Traffic Rank indicator for all the sites you visit." - i.e. we need a way of measuring unique visits to everything
Still, interesting, and good on this guy for bringing it into the public eye.
Not that it's a good idea.