The American Association of Advertising Agencies is gathering at its annual convention as the largest digital ad platform — Google — faces a massive boycott over ad placement next to offensive and extremist content on YouTube.» Subscribe to CNBC: http://cnb.cx/SubscribeCNBCAbout CNBC: From 'Wall Street' to 'Main Street' to award winning original documentaries and Reality TV series, CNBC has you covered. Experience special sneak peeks of your favorite shows, exclusive video and more.Connect with CNBC News OnlineGet the latest news: http://www.cnbc.com/Find CNBC News on Facebook: http://cnb.cx/LikeCNBCFollow CNBC News on Twitter: http://cnb.cx/FollowCNBCFollow CNBC News on Google+: http://cnb.cx/PlusCNBCFollow CNBC News on Instagram: http://cnb.cx/InstagramCNBCAdvertising Giants Talk YouTube Boycott | CNBC