New York (AFP) – Freedom of expression does not extend to issues China deems untouchable, the Taiwanese-Canadian owner of the NBA’s Brooklyn Nets said Monday as he weighed in on the Houston Rockets pro-democracy tweet crisis.

Rockets general manager Daryl Morey posted a tweet Friday featuring the message supporting the pro-democracy protests in Hong Kong, sparking outrage in mainland China and forcing profuse apologies from the team.

Nets owner Joseph Tsai, who made a fortune with Alibaba after co-founding the e-commerce titan and remains its executive vice president, said in a Facebook post that Morey’s tweet was intolerable to the Chinese government and citizens.

While acknowledging the tradition of free speech in the United States, Tsai wrote: “The problem is, there are certain topics that are third-rail issues in certain countries, societies and communities.”

“Supporting a separatist movement in a Chinese territory is one of those third-rail issues, not only for the Chinese government, but also for all citizens in China.”

“Third-rail” is used to describe an issue considered so politically controversial that it is untouchable.

Only a tiny minority of Hong Kong’s pro-democracy movement have ever advocated independence from the mainland. Most simply want full democracy. But as anger towards Beijing and local leaders has grown during the protests the slogan “Liberate Hong Kong, revolution of our times” has become ubiquitous.

Beijing has sought to portray the protests as a foreign-funded separatist movement.

“As a Governor of one of the 30 NBA teams, and a Chinese having spent a good part of my professional life in China, I need to speak up,” Tsai said.

“The hurt that this incident has caused will take a long time to repair.”

Tsai, whose Nets play exhibition games against the Los Angeles Lakers in Shanghai on Thursday and in Shenzhen two days later, said “the Chinese psyche has heavy baggage” when it comes to any territorial threat.

He pointed to China’s suffering in the 19th and 20th centuries at the hands of foreign powers, saying they bullied China into ceding territory and signing exploitative treaties, and — in the case of imperial Japan — brutally invaded the country.

That period is known in China as the “Century of National Humiliation”, ending with the Communist takeover in 1949.

“The NBA is a fan-first league,” wrote Tsai, who completed his takeover of the Nets in September.

“When hundreds of millions of fans are furious over an issue, the league, and anyone associated with the NBA, will have to pay attention.”

The NBA has sought to distance itself from the comments by Morey, who also tried to calm the waters with a string of emollient tweets.

“I have always appreciated the significant support our Chinese fans and sponsors have provided,” Morey said. “And I would hope that those who are upset will know that offending or misunderstanding them was not my intention.”