Activision Blizzard banned a professional Hearthstone player from competitive events and rescinded his winnings after he voiced support for pro-democracy protesters in Hong Kong. The decision has led to sharp criticism from some in the community, including calls for a boycott.

CBS News reports that Ng Wai Chung aka “Blitzchung” was conducting a post-match interview when he shouted, “Liberate Hong Kong, revolution of our times.” Blizzard found this was in violation of its Hearthstone Grandmasters competition rules, and indicated the offending rule:

“Engaging in any act that, in Blizzard’s sole discretion, brings you into public disrepute, offends a portion or group of the public, or otherwise damages Blizzard image will result in a removal from Grandmasters and reduction of the player’s prize total to $0 USD,” the rule reads.

Chung has subsequently been banned from Hearthstone esports for one year, and he’ll need to forfeit $10,000 in prize money from the tournament. Activision Blizzard is partly owned by the Chinese company Tencent. The company also noted that the two hosts were fired. Chung has been a competitive Hearthstone player for years, having placed in tournaments starting in 2017 according to Liquidpedia.

Blizzard is now facing backlash from fans for the decision. The Hearthstone subreddit is currently populated with several heavily upvoted threads from fans saying they’ve quit the game, often referencing how many years they’ve played or how much money they’ve spent. Some have criticized Blizzard for the incident in light of its value statements on plaques outside the main office, which say “Think Globally” and “Every Voice Matters.”

The controversy has only grown in the days since. The company has faced criticism from sitting US Senators and other video game developers, and high-profile players like Brian Kibler and James Kostesich aka “Firebat” have criticized the move as too harsh. Kibler also appears frequently as a host and event caster, and has announced he will no longer be associated with Grandmasters events.

GameSpot has contacted Blizzard for further statement, but it has not responded as of the time of writing.