Whitner says 49ers have NFL's best defense

Daily 49ers blog for NBC Bay Area website: The 49ers' defense had its troubles in the NFC Championship Game and Super Bowl, but safety Donte Whitner still believes San Francisco goes into the 2013 with the NFL's best defense. http://www.nbcbayarea.com/news/local/Whitner-49ers-Have-NFLs-Best-Defense-202706601.html