It looks like your source has disallowed bots from indexing http://m.brne.ws/. You can check out the restrictions in the robots.txt file at http://m.brne.ws/robots.txt. The site's webmaster may have added the restriction recently.
Yahoo! appears to stop YQL queries when the source is listed in the domain's robots.txt file. It would probably be a violation of the site's Terms of Service for YQL to process the query. There probably isn't a technical way around it except contacting the site's webmaster.