Newsweek reported:

And you thought the flap about Super Bowl XXXVIII's halftime show was over Janet Jackson's so-called wardrobe malfunction. Turns out that while jaws were dropping over Jackson's right breast, exposed by duet partner Justin Timberlake at the end of their act, the National Football League was already dealing with another offensive halftime image—the famous, and politically sensitive, still shot of a man blocking a procession of tanks during the 1989 Tiananmen Square protests. The image had just aired as part of an ad encouraging Americans to vote.

(link via Brainysmurf)