We all know by now that Katherine Heigl is not one to be messed with. She proved this yet again with the $6 million lawsuit that she filed against New York Pharmacy giant Duane Reade on Wednesday.

Why is she suing them and what does Duane Reade have to do with Heigl? Well, it all started with a paparazzi photo reportedly shot by a Just Jared photographer.

On March 18, a paparazzi photo was taken of Heigl entering a NYC Duane Reade pharmacy with two of their shopping bags in her hands.

Duane Reade got hold of the photo and used it to promote their store on both their Twitter and Facebook pages with the caption "Love a quick #DuaneReade run? Even @KatieHeigl can't resist shopping #NYC's favorite drugstore."

Heigl was not happy with this and has sued the drugstore for using her name and likeness for its commercial advertising without her approval.

The lawsuit states, "The Heigl photograph is a typical 'paparazzi' shot, depicting plaintiff walking on the street in New York City, in a private moment looking away from the camera. ... Use of plaintiff's image under these circumstances improperly exploited plaintiff's name and likeness, as a celebrity, for defendant's commercial advertising and purposes of trade, without authorization."

According to the complaint, all proceeds from the lawsuit will be donated to The Jason Debus Heigl Foundation that honors Heigl's brother who was killed in a car accident and focuses on animal welfare.

This isn't the first time the Emmy-winning actress has been vocal about her disapprovals. In her 2008 interview with Vanity Fair, Heigl expressed that she did not like her role in the Judd Apatow movie Knocked Up.

"It was a little sexist," she says. "It paints the women as shrews, as humorless and uptight, and it paints the men as lovable, goofy, fun-loving guys. It exaggerated the characters, and I had a hard time with it, on some days. I'm playing such a bitch; why is she being such a killjoy? Why is this how you're portraying women? Ninety-eight percent of the time it was an amazing experience, but it was hard for me to love the movie."

The 35-year-old actress also stirred up controversy when she turned down her shot at winning another 2008 Emmy for her role in Shonda Rimes's Grey's Anatomy because she felt that "she wasn't given the material to warrant an Emmy nomination." Heigl later left the TV show in pursuit of her movie career.

What is your opinion? Did Katherine Heigl go too far with this lawsuit? Share your comments below.