More stars have been revealed to be part of the FBI's probe into hacked nude photos.

The celebrities, all female, now include Selena Gomez, Demi Lovato Christina Aguilera, Vanessa Hudgens, Scarlett Johansson, Ali Larter, Busy Philipps, Miley Cyrus, Emma Caulfield, Addison Timlin and Renee Olstead, according to TMZ.

So how do hackers illegally obtain these very private, personal photos?

“By far the most common method is quite simply password theft. The problem is that with advances in computer processing power, computers are now able to process larger amounts of data in a much smaller amount of time. A password is just a bunch of characters, and it can be relatively easy to program a script that can run through all possible permutations until a hacker achieves success,” IT expert and software developer, Yasser Hamed, explained. “This problem is compounded by the fact that people tend to use passwords that are easy to remember and which they can relate to such as pet names, family members, school they went to etc. With the advent of social networking such as Facebook and Twitter, this type of information is even easier to attain.”

PICS: Jessica Alba

PICS: Scarlett Johansson

PICS: Christina Aguilera

The other common hacking approach is a little more elaborate and involves planting a malicious computer program known as “Trojan horse” onto a target’s computer.

“It can be used to control the host remotely and hence allow the hacker access to the data stored on hard drives. A Trojan Horse can even be used to activate a webcam on the infected machine and allow the hacker to attain photographs from inside the premises without you even being aware,” Hamed said. “All a Trojan horse needs to succeed is for the user to execute it."

Yet given that celebrities live their lives in the public eye, isn't it just plain stupid to be taking naked photos and videos in the first place?

“I always tell my celebrity clients that the downside of being famous is that people are interested in [seeing your naked photos], so they should be guarded in these situations. [If they don’t like that] then they should drop out of sight, stop traveling the world, stop making all that money so no one cares about them anymore,” Los Angeles entertainment and IP expert attorney Jonathan Blinderman told Pop Tarts “But the reality is they like their lives and the cash they make so they choose to be in the world but they should be guarded. Keep them off phones. Keep them encrypted and not accessible to hackers.”

If the hackers are arrested and convicted, they face a range of possible punishments.

“The federal punishment for hacking into computers ranges from a fine or imprisonment for no more than one year to a fine and imprisonment for no more than twenty years,” Los Angeles attorney David E. Wohl told Pop Tarts. “Basically the punishment depends on whether the hacker has a history of hacking, whether he or she as any prior convictions and how egregious, or serious, the offense was.”

Any celebrities whose accounts were hacked would also most likely have to testify in court.

“They will have to take the witness stand to authenticate the photos of themselves,” Wohl added. “That obviously could be rather humiliating.”

If the same hackers that are currently being probed by law enforcement officials had anything to do with the 2007 Hudgens scandal, in which full-frontal pictures take of a then-underage actress hit the worldwide web, the situation could become much more serious.

“If they were taken when Vanessa, or any of the stars, were under 18 years old, the stealing or hacking of those photos and transmitting them could lead to federal charges of transmission of child porn being filed against the cyber-thief,” Wohl continued. “The penalty is far more severe for this crime. The penalty ranges from one to a maximum of fifteen years in federal prison.”

Reps for the actresses did not respond to our request to comment.

- Deidre Behar contributed to this report.