Yahoo! must have criteria it uses when hiring writers and editors. It’s not an ability to spell, use correct grammar, accurately synthesize a news event, or punctuate a sentence. Another criterion that Yahoo! doesn’t use? The ability to select the correct word when writing for the Yahoo! front page:
The American Heritage Dictionary (which you’ll find on Yahoo!, but Yahoo! writers haven’t yet discovered) says:
Like the analogous etymological plurals agenda and data, criteria is widely used as a singular form. Unlike them, however, it is not yet acceptable in that use.