On 22 September 2014, in response to the arrest of student protesters in the Hong Kong
Umbrella Movement Cheng returned home from his studies at
Queensland University of Technology to participate in the protest. In November 2014, Cheng went back to
Brisbane to lead a rally in support for the Umbrella Movement during the
2014 G20 Brisbane summit. On the 16th, the four-hour rally on a lawn outside the summit venue attracted participation by many overseas students from Hong Kong,
Taiwan and Mainland China. On 6 December 2014, Cheng established Student Front, a
student activist organization to fight against the "stage power" and to remain at the frontlines after the
Hong Kong Federation of Students and
Scholarism quit the protests. He wrote an article that indicated he was arrested on 26 December 2014 and not granted
bail. After the Umbrella Movement, Cheng continued with numerous protest activities, such as
gau wu and the movement against
parallel trading. He was arrested on several occasions and found it difficult to obtain bail. He was then banned from entering
Mong Kok by a court order. On 2 March 2015, Cheng announced that Student Front was dissolved and warned other activists not to depend completely on "student activism organizations". On the morning of 27 April 2015, Cheng was involved in a dispute with supporters of
Avery Ng, the vice-chairman of the
League of Social Democrats, outside
Mong Kok Police Station regarding the progress of the Umbrella Movement. On 20 August 2015, Cheng was convicted of obstructing bailiff officers from clearing
occupied roads in Mong Kok on 26 November 2014, and sentenced to 21 days' detention. On 20 November 2019, Cheng was arrested by Hong Kong police when he tried to escape from the
siege of the Hong Kong Polytechnic University. He was eventually convicted for taking part in a riot, and sentenced to 3 years and 8 months in prison on 11 February 2023.
Disqualification in 2020 Legco election Five weeks ahead of the (subsequently postponed)
2020 Hong Kong Legislative Council Election, on 30 July 2020, as Cheng preparted to stand, the government stated that he was among a dozen pro-democracy candidates whose nominations were 'invalid', under an opaque process in which, nominally, civil servants –
returning officers – assess whether, for instance, a candidate had objected to the enactment of the
national security law, or was sincere in statements made disavowing separatism. ==See also==