At least 12,000 demonstrators marched on Sunday to protest a planned anti-subversion law they fear will undermine Hong Kong's freedoms and put the territory more firmly under the thumb of mainland China.
"We don't want darkness to fall on Hong Kong," said Lee Cheuk-yan, a legislator and union leader, as the protesters advanced to Hong Kong government headquarters, waving signs, chanting and popping balloons.
Many sang the civil rights anthem "We Shall Overcome" in the peaceful demonstration.
Police said 12,000 people had turned out, while organizers put the number at 25,000.
The march was enormous by Hong Kong standards — rivaled in recent years only by the crowds that turn out each June 4 to commemorate China's bloody crackdown on protests in Beijing's Tiananmen Square in 1989.
Ever since Hong Kong was returned from British to Chinese sovereignty in July 1997, it has been required by its mini-constitution to outlaw subversion, sedition, treason and other crimes against the state.
The government recently began work on the legislation. Critics say officials are going too far — apparently to please Beijing — with a law so loosely written it would let the authorities trample on people's freedoms or ban groups the government doesn't like.
Hong Kong Secretary for Security Regina Ip has dismissed such concerns as groundless, saying the territory's laws also protect civil liberties, and that will not be changed.
Many here don't believe the government.
"I don't want Hong Kong to become like China," said Philip Cheung, a 48-year-old civil servant who joined Sunday's demonstration.
"The rights we have are not guaranteed in the future," grumbled a 25-year-old bank clerk, Sam Ho.
The demonstrators formed a line several people deep that stretched for 6 kilometers (3.5 miles).
Since Hong Kong's handover, free speech rights have been guaranteed under a government arrangement dubbed "one country, two systems," and there are hundreds of demonstrations every year, mostly involving dozens of people or fewer.
The size of Sunday's demonstration indicated massive discontent among ordinary Hong Kong citizens over the bill, which the government hopes to pass by July.
The Hong Kong Security Bureau said the protest proves the government's contention that local civil liberties are intact.
"Today's rally bears testimony to the freedom of expression and the right to demonstrate which are enjoyed by Hong Kong residents," the bureau said in a statement. "These rights and freedoms are guaranteed."
The protest snarled traffic in the city center in the late afternoon, but appeared to be winding down peacefully early Sunday night.
"Use your courage and stand up," some activists shouted, amplifying their message with loudspeakers mounted on a truck. Others displayed a mock guillotine calling the anti-subversion law "a knife above Hong Kong people."
Pro-democracy politicians and human rights activists opposed to the law have been joined by some in the business community who fear the exchange of some financial information could theoretically be targeted and wreck Hong Kong as a business center.
Wealthy newspaper publisher Jimmy Lai marched on Sunday, saying the law was "like an invisible, tightening collar."
Religious activists and members of the Falun Gong spiritual sect — which is outlawed in mainland China as an "evil cult" although it remains legal in Hong Kong — were also out in force