The fans sat behind the backboard near the Nets' bench at Barclays Center in their 123-107 loss to Toronto on Friday night.
The Nets returned this week after playing exhibition games against the Los Angeles Lakers in Shanghai and Shenzhen. The games were not televised in China after relations between the NBA and Chinese officials became strained following Houston Rockets general manager Daryl Morey's tweet in support of pro-democracy protesters in Hong Kong.
One sign was aimed at LeBron James and Nets owner Joe Tsai, the co-founder of the Chinese e-commerce giant Alibaba, who were critical of Morey's tweet. Tsai wrote a Facebook post explaining why the since-deleted tweet was upsetting to the Chinese.
Nets guard Kyrie Irving said he understood why the protesters came to the game.
"I think that when you think about communities across the world, I think that a lot of people would stand for world peace," he said.
"Government gets involved and impacts different communities in different ways. The reality is that as individuals it's our job to stand up for what we believe in. I understand Hong Kong and China is dealing with their issues respectively, but there's enough oppression and stuff going on in America for me not to be involved in the community issues here as well."