Blockchain analyst Specter has reported multiple complaints regarding the cryptocurrency exchange BTCC, where users claim their accounts were locked, restricted, or disabled after making profits. One notable case involves a user with over $500,000 in their account, who found their assets cleared upon regaining access, with no clear explanation from BTCC. Specter highlighted that while BTCC attracts new users through influencer promotions and advertising, several users have reported unexplained account restrictions, urging caution against low-tier 'betting-type' exchanges.