Leung Kin-fai (Chinese: 梁健輝; 1971 – 1 July 2021), was a Hong Kong merchandiser known for stabbing a 29 year old police officer in Causeway Bay and committing suicide immediately afterwards.

[11][12] On his person was a USB drive where Leung had left suicide notes alleging that the police had harboured criminals, committed atrocities, and said that there was a lack of checks and balances under the system.

[15][16] The shares of Vitasoy, which are listed on the Hong Kong Stock Exchange, fell sharply on the day of the announcement, after Mainland Chinese social media users on Weibo called for a boycott of its products.

[17][3] The Mainland Chinese market accounting for two-thirds of the company's revenues,[2] Vitasoy disowned the memorandum and issued a public apology saying that it was highly inappropriate and was not approved by the firm.

[3] Police said that mourning the individual was an attempt “to glorify, romanticise, make heroic and even rationalise the blatant violence of the attacker”, and could be in breach of the national security law.

[3][20] On 7 July, the students' union of the University of Hong Kong passed a motion which expressed "deep sadness" at the death of Leung, and appreciation of his "sacrifice",[21] which the Security Bureau condemned as "no different from supporting and encouraging terrorism".

[24] Eric Cheung Tat-ming, principal lecturer at the University of Hong Kong Faculty of Law, dissented from the justification of the ban, and immediately resigned from the council.

[29] In late August, Vitasoy asked its employees to agree to the collection of highly personal nature such as names and details of family members, including memberships or affiliation of associations and different organisations, failing which the company might not be able to pay workers.