BEIJING - China's jailing of a Hong Kong reporter as a spy reflects a deepening dilemma for the communist government: how to tighten control over information in an increasingly open, Internet-savvy society.

Ching Cheong, a correspondent for The Straight Times in Singapore, was sentenced Thursday to five years in prison after being convicted of selling secrets to Taiwan, the self-ruled island that Beijing claims as its territory.

His conviction came amid a government campaign to rein in a freewheeling press that has seen dozens of journalists and Internet essayists jailed. But the crackdown goes further: China is also tightening controls over legal activists, charities and even mapmakers, whom a state news agency accused this week of threatening national security with unauthorized surveying.

The effort highlights the communist leadership's desire to put the brakes on the societal changes that have been occurring since economic reforms started 25 years ago. In exchange for a more vibrant economy, the government has been forced to ease social controls, giving Chinese the freedom to live where they want, travel or study abroad and post their opinions on the Internet.

While much of Chinese society is hurtling forward to catch up with the West, the leadership is trying to claw them back. The friction has created some notable casualties:

Ching, who plans to appeal, was accused of selling unspecified "state secrets and intelligence" to a Taiwanese foundation that was really a spy agency. The state-run Xinhua News Agency said Ching contacted the foundation, which it didn't name, while working as a reporter in Taiwan.

Ching's wife said earlier he might have been targeted because of his contact with a researcher with access to records of discussions among Chinese leaders.

Last week, a Chinese researcher for The New York Times was acquitted on a charge of leaking state secrets but jailed for three years on a fraud accusation. The charge against Zhao Yan was believed to stem from a Times report on plans by former leader Jiang Zemin to give up his last major post.

China is believed to have at least 32 journalists in jail, mostly on charges of violating vague security or subversion laws.

Control over information always has been a key weapon in the Communist Party's arsenal. But since the late 1990s, China's state-run media outlets have been given more editorial liberty in hopes of making them commercially successful and ending their need for subsidies.

After the government admitted to botching a cover-up of the SARS epidemic in 2003 and called for more transparency, the media took up the challenge. But the burst of freedom didn't last. Within months, Hu Jintao, who replaced Jiang Zemin as president and Communist Party chief, battled back.

Members of the collective leadership Hu heads have argued that only one-party rule, without scrutiny by an independent media, can provide the stability China needs to prosper. Hu himself, in a 2004 speech to a closed-door party meeting, praised North Korea's and Cuba's media controls.

Events at home and abroad are contributing to a siege mentality. Public protests over graft, farmland seizures and other complaints in China are soaring, worrying the government that aggressive reporting could add fuel to the fire. Democratic movements that toppled autocratic governments in Ukraine, Georgia and Kyrgyzstan, as well as President Bush's mission to spread democracy worldwide have added to Chinese fears of encirclement.

In trying to restrict what Chinese people read and hear, the government has shut down hundreds of small publications and tightened rules on Web content. Reporters and editors have been fired for reporting on protests over corruption and other complaints. In 2005, a reporter was sentenced to 10 years in prison after he sent an e-mail about a memo at his newspaper on media restrictions.

The spying charges against Ching and Zhao could represent a government warning that, with the help of Chinese employees, foreign news organizations are getting too much access to official information.

After a manager of China's social security fund was executed in April on charges of spying for Taiwan, government employees were required to watch a video about his case that emphasized the need for them to protect secrets, according to reports on state Web sites.

EDITOR'S NOTE: Joe McDonald has reported from China for The Associated Press since 1996.