I understand many people have been wondering about this small detail about posting links to media that isn't owned by the person posting. One key consideration is that search engines like google do this very regularly - provide links to web addresses they don't own. A simple link to a website, is however different than a link to media content and a video player like the one that youtube links provide. Whenever linking content, it is a good idea to provide credits and citation for the work you are using.
Here is a link to a an article that explain why this is 'probably' legal, although it is a blurry topic: https://lorelle.wordpress.com/2006/07/06/do-you-need-permission-to-link-to-someones-content/
(source included in link. blog writing within the link was written by lorelle on her wordpress blog hosted on wordpress.com)
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