there was a bright spot though, facebook had its best day since its stock market debut back in may. makes our producer jack very happy. also, many facebook employees who were only rich on paper will have real wealth now. today their so-called restricted stocks units convert into stock. with a cash value of $5.2 billion. the shares will remain locked up until monday. owners can then cash in by selling them on the stock market. enjoy all that green, facebook. well, book lovers across the country are checking their accounts after the startling security breach at barnes & noble. >> little did they know they swiped their credit card at the largest bookstore chain, tech savvy thieves were swiping their personal information. here's abc's pierre thomas. >> reporter: barnes & noble announced it has been the victim of a massive sophisticated scheme targeting credit and