A customer tries out the Apple iPhone 5 inside the Apple Fifth Avenue flagship store on the first morning it went on sale on September 21, 2012 in New York City. - 

When you buy a phone and sign up for a contract with a cell phone company, most phones are set up to only work with that carrier. Unlocking it means that you and your phone are free to join any network. But doing this without your carrier's approval is now illegal. Carl Howe is the vice president of research of Yankee Group.

"The people who this addresses are people who technologically sophisticated," says Carl Howe, vice president of research at Yankee Group. "They like to switch operators frequently.

The unlocking process has largely existed in a grey market of sorts. You could find information about doing it online or pay someone to do it for you. So this law might push more consumers to work with their cell provider.

"It's kind of the same question as how much does copyright law deter people from downloading things illegally on the internet," says Kevin Boyland, a telecom industry analyst at Ibis World. "It's very much on a consumer by consumer basis."

Like with illegal downloads, Boyland says most individuals aren't likely to face charges or penalties. It's the businesses offering these services that might need to look out.

Follow Tracey Samuelson at @tdsamuelson