Here are some of the recent high-profile cases:

'One China'

Hong Kong flag carrier Cathay Pacific was heavily pressured in a campaign led by state-run media in August after Chinese authorities deemed the airline's staff too vocal in their support of the protesters.

The airline's then-chairman John Slosar initially insisted he "wouldn't dream" of telling his staff what to think - but Chinese threats to blacklist the carrier forced a U-turn and Slosar stepped down last month.

In recent weeks staff have described deleting their social media accounts, fearful colleagues might inform on them while Cathay announced it had sacked several staff linked to the protests.

US jeweller Tiffany also came under pressure after a tweet showing Chinese model Sun Feifei covering her eye was interpreted as a sign of support for the Hong Kong protests.

Protesters in the city have adopted the pose to indicate police violence.

The picture of Sun - who was wearing a Tiffany ring on the hand covering her eye - was removed by the brand.

'Wrong' labels

Under pressure from Beijing, a growing number of companies and international airlines - including Delta and American Airlines - have also edited their websites to refer to the self-ruling democratic island of Taiwan as "Taiwan, China" or "Chinese Taipei".

Hotel chain Marriott's website in China was also shut down by the authorities for a week in 2018 after a customer questionnaire listed Taiwan, Tibet and Hong Kong as separate countries, prompting the hotel chain to apologise and change the wording.