This is most noticeable when you try to use the Social Advocacy feature to link to a YouTube video.  When your users try to use Social Advocacy to share the link, they will be able to see the specific video on Facebook and Twitter, but not LinkedIn.  LinkedIn will only allow users to share the YouTube Homepage.  To fix this, make sure you are using the Share Link on YouTube.  Find the video you want to share and click the Share arrow at the bottom of the video.  This will provide you with an embed link.  Use this link instead of copying and pasting the "watch" link at the top of the YouTube screen.  

This may happen in other areas of PoliteMail and Outlook when embedding YouTube links, so always make sure you use this method.