Actress Scarlett Johansson is threatening legal action against anyone who posts the nude photos of her that hit the Internet on Wednesday.

Johansson's lawyer, Marty Singer, has issued letters to websites that are running the photos — one of which shows her topless, another shows her standing with a towel covering her front side with her butt exposed in a mirror — noting that they must take the photos down and that they are "stolen copyright protected private photographs," according to TMZ.

The lawyer's statement continues, "The highly personal and private photographs at issue capture our client self-posing in her own home in a state of undress and/or topless. If you fail to comply, you will be acting at your own peril. Please govern yourselves accordingly."

E! News confirmed that the FBI is currently investigating who may have hacked the actress' computer or other device and leaked the photos. "The FBI is investigating a person or group responsible for a series of cyber intrusions of high-profile figures," FBI spokeswoman Laura Eimiller said. "This would include many devices — could mean a computer, desktop, laptop, iPad, cell phone ... intrusions into personal online accounts too."

Johansson is one of many celebrities who have been targeted by a ring of hackers who gained access to their personal information, including Christina Aguilera, Miley Cyrus, Jessica Alba, Selena Gomez and Demi Lovato.

On the same day that Johansson's photos hit the Web, TMZ reported that Mila Kunis had also been hacked. There are reportedly four photos of the actress floating around, including one of the actress in a bathtub and one of her with an unidentified male. There are also reportedly two photos out there of Kunis' "Friends With Benefits" co-star Justin Timberlake. He is lying in a bed in one and wearing pink underwear on his head in another. Kunis is not featured in the pics with Justin.