I wanted to see about the US-Russia soccer friendly, and on this page, I clicked on the link that reads “Michael Bradley scores on an excellent volley” and it takes me to a page I’ve never seen before called “Yahoo! Guesthouse” where you are prompted to enter a username and a passphrase, whatever that is.
To answer the unspoken question: someone at Yahoo! screwed-up the link, and it goes to the wrong URL. The URL is on Yahoo!'s internal management tool, which is why you received a username/password prompt when you followed it.