The top court has begun hearing an appeal whether five prominent pan-democrats who were fined for speaking on pirate station Citizens' Radio in 2008 should have been prosecuted.
The five defendants - the Democratic Party's Emily Lau Wai-hing and Lee Wing-tat, People Power's Wong Yuk-man and Albert Chan Wai-yip, and Labour Party's Lee Cheuk-yan - were each fined HK$1,000 in 2009 for staging a radio broadcast in April 2008 on a busy Mong Kok street, a decision that the Court of First Instance upheld.
All but Democrat Lee won re-election to the Legislative Council last month.
Their four-year legal battle culminated in a final appeal, the top court heard yesterday.
At issue is whether speaking in front of a microphone connected to an unlicensed station was considered as delivering or transmitting a message, if at all.
The court is to decide whether Section 23 of the Telecommunications Ordinance, under which the five are charged, dealt only with telegrams but not the radio.
The section forbids the transmission or receipt of a message via an unlicensed telecoms means.
In the meantime, the defendants' challenge of the constitutionality of the 76-year-old ordinance was set aside.
The group - originally including late veteran lawmaker Szeto Wah - railed against the government's delay in reviewing the 76-year-old Telecommunications Ordinance while allowing other radio stations to operate.
The one-hour programme on FM radio, which also went on the internet, was aired via transmission equipment set up on a Lion Rock hillside, which provided coverage over most of Kowloon and northern Hong Kong Island. In the heart of Mong Kok's main shopping area, it drew a crowd of about 100.
Martin Lee Chu-ming SC, founder of the Democratic Party, representing three of the five defendants, insisted yesterday that the word "delivery" adopted in the ordinance was inapplicable to a radio context as it meant "handing over".
Prosecutor Johnny Mok Shiu-luen SC said: "The 1936 ordinance is in no way inconsistent with [my] interpretation - it already had contemplated radio as one mode of telecommunications."
Mok faced fierce questioning from most of the five justices.
"[What] if one speaks into a microphone and says, 'Hi, mum, it's me.' Who's the transmitter?" Mr Justice Henry Litton asked.
The justices reserved their judgment for a later date.