[Tether CEO Paolo Ardoino: 4.5 Million USDT Frozen in Connection with Mercado Bitcoin Security Incident] Tether CEO Paolo Ardoino announced that Tether has frozen 4.5 million USDT related to the Mercado Bitcoin security incident. Mercado Bitcoin stated that a security incident occurred on one of its systems, but customers did not suffer any losses or data breaches. As a precautionary measure, the platform has temporarily suspended deposits and withdrawals.