Dave Hogan/Getty Images

About year and a half ago, Passport blogged about the opening of the $40 million Oprah Winfrey Leadership Academy for Girls in South Africa, funded by -- you guessed it -- Oprah. The project was launched in celebrity fanfare, highlighting Oprah for the cultural and economic world power she has truly become.

Much to Ms. Winfrey's dismay, however, extravagant spending has been followed by spectacular scandal. A former head mistress from the school is suing the famous talk-show host for $250,000.

About this time last year, allegations of sexual abuse in the school surfaced (Oprah weeped when she heard). Virginia "Tiny" Makopo -- then a school employee -- was arrested for counts of abuse to which she pleaded not guilty. But Oprah was not quite done cleaning house. Nomvuyo Mzamane, the former head mistress, was accused of covering up the scandal. Now jobless and "depressed," Mzamane is sueing Oprah for defamation. She says she never knew the abuses were going on.

The price tag on the lawsuit is barely a drop in the bucket for the $2.5 billion celebrity, but Oprah should worry a lot more about that the tougher-to-quantify damage to her brand.