In this instance, they did not get permission first. From the article: "...posted it to their website with other UGC content. It was only much later that Crocs

In this instance, they did not get permission first. From the article: "...posted it to their website with other UGC content. It was only much later that Crocs sought explicit permission..." And that's unacceptable. The TOS of these sites with embeddable content have content creators licensing their creations for embedding, provide attribution when embedded correctly, and generally attempt to be fair in the arrangement. Explicitly taking content from any place online simply because it was publicly accessible and dropping it into your site without the proper embedding code is not acceptable. It doesn't matter that there's a mention of a hashtag that the company's marketing department encouraged the creator to use.