As the U.S. government shutdown continues, celebrities are showing their support for Obamacare aka the affordable healthcare act. Nina is one of those celebrities who tweeted a topless photo of herself voicing her opinion. Don't get too excited though, Nina strategically covered her assets with a small sign. The list of celebrities that use their fame to voice their opinion is too large to count, but we found an interesting topless PETA ad featuring Joanna Krupa that we thought might give Nina a run for her money. Which activist do you think is hotter, Nina or Joanna?