Just when you thought you heard it all, there's a new way to hack into people's voicemails and disguise your voice and phone number. It's technology that could cost one high profile publicist her freedom, and she's not the only celebrity to get caught.

According to its Web site, Spoofcard is a program that can not only disguise your phone number, it can also disguise your voice.

It's fun for many. You just type in your phone number, then the phone number of the person you want to "spoof", and then whatever alias number you want them to see.

"It's not illegal, but it can be used for illegal purposes," said Gene Vinson, manager of San Diego Computer Consulting.

Vinson said the problem with the program is the ability to hack into other voicemails.

"If you dial someone's cell phone with their cell phone number , you're going to get their voicemail. That's how this program works," said Vinson.

And because of that, it's gotten some celebrities in hot water. Lindsay Lohan and Paris HIlton had their accounts terminated for misusing Spoofcard. But the most recent case involves a former Dolce and Gabbana publicist, Ali Wise. She allegedly used the program to hack into the voicemail of her ex-boyfriend's new girlfriend. Not only is that illegal, but Wise could face four years in prison for felony computer trespassing and eavesdropping.

" It seems in my opinion, is that it's inviting people to violate the law. Why do you want it ? You want it to hide your identity and probably for some improper purpose," said law professor David Steinberg of the Thomas Jefferson Law School.

Users must sign an agreement not to use the program illegally.

You would think that with all the legal issues though, people would shy away from using Spoofcard. Not so, according to experts. Some said there are lots of practical applications for the program.

"There are certainly cases where you don't want your personal cell phone to be recorded in caller ID. This is a great program to do that," said Vinson.

Experts also advise that the best way to protect yourself from people hacking your voicemail is to simply put a password.