On June 5, 2021, PolyButterfly, a decentralized financial protocol based on Polygon, disappeared. Its website has been closed, and its Twitter account and Telegram chat history have been deleted. Before this mysterious disappearance, it was revealed that the PolyButterfly code had a dangerous backdoor that allowed the product team to remove customer liquidity. According to RugDoc, the scammers stole more than 600 ether, or more than $1,500,000.