Someone has created a YouTube channel titled ‘WWDCVideos‘ and uploaded 98 WWDC 2013 session videos to YouTube.
Earlier, this channel appeared to be legitimate as the link was tweeted out by Safari and WebKit engineer Timothy Hatcher (via MacStories), but his tweet has now been deleted because these videos are unauthorized as noted by Apple (oops), as told by the company to iMore’s Rene Ritchie:
@pbur I was informed thusly by Apple.
— Rene Ritchie (@reneritchie) July 15, 2013
These videos are in violation of the developer NDA so these are unofficial rips on YouTube. The channel will most likely have the videos removed.