It's not that Yelp claims ownership of the images. Essentially, when you upload an image to yelp you place it in the public domain. That's how I read their terms and conditions.
Nevertheless, it's a good practice to reach out to the reviewers. They do a lot hard work and should receive acknowledgment for their efforts.
They don't claim "ownership" as in it belongs to them and not to you. However they do claim the rights to use things you post in various ways (emphasis mine):
We may use Your Content in a number of different ways, including publicly displaying it, reformatting it, incorporating it into advertisements and other works, creating derivative works from it, promoting it, distributing it, and allowing others to do the same in connection with their own websites and media platforms ("Other Media"). As such, you hereby irrevocably grant us world-wide, perpetual, non-exclusive, royalty-free, assignable, sublicensable, transferable rights to use Your Content for any purpose. Please note that you also irrevocably grant the users of the Site and any Other Media the right to access Your Content in connection with their use of the Site and any Other Media. Finally, you irrevocably waive, and cause to be waived, against Yelp and its users any claims and assertions of moral rights or attribution with respect to Your Content. By "use" we mean use, copy, publicly perform and display, reproduce, distribute, modify, translate, remove, analyze, commercialize, and prepare derivative works of Your Content.
Yelp claims the right to let "Other Media" use the content. They way I read this is that a site would need Yelp's permission to use the content on their own sites or outlets. I assumed Metro Jax had Yelp's permission to use the photos, which sounds like it's not the case. Looking at the two articles, the pictures aren't attributed even to Yelp, let alone the user who created them. Definitely bad etiquette to quote Ennis. The moral of the story is (1) don't upload your pictures to a website if you don't want them to be used, and (2) you didn't take the picture, credit the person who did, especially on a site like this that brings in money.
