JACKSONVILLE, Fla. -- Hundreds of thousands of children write letters to Santa Claus every year, and many of them even get responses back from North Pole, Alaska.

But that might stop soon because of a sex offender slip up.

A national program run by volunteers sorts through letters addressed to "Santa North Pole" and forwards them to the tiny Alaska town.

Workers there send a letter from Santa back to the child post-marked "North Pole."

But postal workers in Maryland discovered one of their volunteers was a registered sex offender who could've had access to children's names, ages and addresses.

It was a big enough scare to tighten the rules nationwide, including in Jacksonville.

"We have changed our Operation Santa, that's what we call it," said Lindy Green, who works for the U.S. Postal Service in Jacksonville. "Mainly it's just to protect the privacy of children."

Green said the local Santa letter program is not stopping like it is in other parts of the country, but it is making changes.

In the past, charities would take letters from children who appeared to be in need and fulfill their wishes.

But the USPS said now it has to be careful.

"The way it is now, none of the private info is released, names, age, address, what school the kid attends," Green said. "None of that info is released to private agencies."

Green said the postal service will work hard to make sure it continues the tradition.

"It's very important for those kids to get that letter, and we want to make sure we do that," Green said.