A big rise in the number of arrests of demonstrators has prompted a group of legal professionals to produce a handbook to explain their rights.
The new Hong Kong Civil Liberties Union has published the five-page booklet in Chinese  and English . It follows a seven-fold increase in the number of protester arrests last year, from 57 in 2011 to 440.
The group's spokesman is Craig Choy, 34, a former criminal law barrister who now works as an in-house lawyer.
He said: "We noticed that more people were being arrested at protests, so that's why we gathered this publicly available information so they know their rights." He said the group was not affiliated with any political party and the booklet was also applicable to daily life, not just for protesters.
"We aren't just talking about pro- and anti-government protesters. It's about rights under the International Covenant on Civil and Political Rights," he said.
"Everyone has an opinion and I welcome protests because they help society to work out a compromise." Choy estimated that the booklet, published just before Christmas, has been downloaded about 10,000 times.
During the New Year's Day protests, one Facebook group, Never Forget June 4, with a slogan of "Unite against CY", printed out 3,000 copies of the booklet and distributed it to protesters.
But Choy emphasised that the booklet was for everyone.
He said: "Pro-government protesters can use it too. We welcome them, actually".
But Chan Ching-sum, convenor of the pro-government group Caring Hong Kong Power, said the handbook would be of little use to her group.
"If you have seen our demonstrations, you will know that we are very peaceful and we follow police orders," she said.
"We would not run onto the street and cause disorder. This guide is not for us."
The booklet provides details of the specific articles in the Basic Law as well as the city's Bill of Rights relating to freedom of speech, peaceful assembly, procession and demonstration.
It also provides a comprehensive guide to a citizen's rights when they are stopped by police, searched and arrested in a public place.
Choy said the group planned to set up as a formal organisation soon, and invited legal and non-legal professionals to join.
Latest police figures show the number of public meetings and processions increased from 1,190 in 1997 to 6,878 in 2011.
More protesters were prosecuted in 2011 under the Public Order Ordinance - which carries harsher penalties than other laws commonly used in such situations - than in any year since the handover.
Police laid charges under the ordinance against 45 protesters, compared with a total of 39 between 1997 and 2010.