Tens of thousands of Colombians marched on Monday -- at home and abroad -- to demand that the country's largest rebel group stop kidnapping people and release those it is holding. The protesters denounced FARC's [Revolutionary Armed Forces of Colombia] use of violence and kidnapping in its bid to overthrow the Colombian government. The Marxist group is holding hundreds of hostages, including more than 40 high-profile captives. Producer Zulima Palacio traveled recently to Colombia to examine the kidnapping problem. Mil Arcega narrates her story.

Announcer: Ya las lineas estan todas copadas ("The lines are all taken now.")

For the past 14 years, every Saturday night, this unique radio show has been on the air. "Las Voces del Secuestro," or "Voices of Kidnapping," is directed at kidnap victims in Colombia. Maria Isabel Campos is a program coordinator.

Campos explained the program format. "Beginning at 12 midnight, the family members of all the people in captivity call our phone lines."

For six hours -- until early Sunday morning -- the phone lines never stop blinking. Many family members simply show up at Caracol radio studios in Bogota. They want to send messages of hope or family news to loved ones in captivity.

One boy wants to reach out to his uncle. He would like for his uncle to know, "That I love him very much and wish to recover the lost time with him," he said.

Olga is the mother of Alberto Plazas Adame. Kidnappers abducted him six years ago and she has not heard from him in the last five. She says she knows he is still alive. "I know it in my mother's heart. I know he will come back. I can hear him. I know we will meet again and we are waiting for him."

Another call comes from New York. It is Melanie Betancourt, the daughter of French-Colombian politician Ingrid Betancourt. The FARC kidnapped her in 2002 as she campaigned for the Colombian presidency.

Betancourt appeals to her mother, "Mom, we all need you here. 2008 is going to be the one for your freedom. Hold on there. I do not let you go Mom, so please hold on to your life. I love you. Take care of you..."

For nearly four decades, guerrillas and terrorist groups, paramilitary forces and common criminals in Colombia have kidnapped thousands of people. .

"The kidnapping in Colombia means nearly 23,000 victims during the last 11 years and more than 3,000 people in captivity today. It also means about 300 children kidnapped and, above all, this means a huge damage to the families and the society," says Olga Lucia Gomez, who is the executive director of the private group Free Country Foundation.

Gomez says there are many reasons why kidnapping is such a problem in Colombia. The simplest is that the kidnappers get away with it. Some do it for money. Others for political reasons.

But she says in nearly half the cases, the kidnappers make no demands at all -- the victims are likely murdered. "Out of the 3,000 hostages today, 770 are held by the FARC according to officials records at the Liberty Fund. The numbers are unstable. We don't know the authors in nearly 1,200 cases." Colombian officials believe another terrorist group, ELN, and common criminals are behind other kidnappings.

Harlem Andres Enao is the director of Liberty Fund, a government organization that gathers statistics and information about kidnappings in Colombia. "According to our data base, since 1996 to date, 1,307 people died in captivity, 13,808 citizens were freed and 4,487 were rescued [by the authorities]," Enao said.

Last month, FARC freed two Colombian politicians [Clara Rojas and Consuelo Gonzalez] after holding them for years. Venezuelan President Hugo Chavez mediated the release. He also has offered to help gain freedom for other FARC captives, despite strains in relations with Colombia. Mr. Chavez says FARC rebels are not terrorists, but have political goals that need to be respected.

The two newly released kidnap victims brought news of other hostages, including a letter from Colonel Luis Mendieta, kidnapped by FARC nine years ago. Mendieta's wife, Maria Teresa, read her husband's letter in public. She said, "My husband said in his letters that neither the humiliation of kidnapping or the chains that kept him tied up hurt him as much as the evilness of bad men and the indifference of the good man."

Many Colombians cast indifference aside this week. They not only marched in Bogota, demanding an end to the epidemic that plagues their nation, but also in Venezuela, Europe, Japan and the United States The idea started simply about a month ago on the social networking web site "Facebook."