The American Registry for Internet Numbers (ARIN) discovered a fraud scheme in late-2018 through which 757,760 IPv4 addresses worth between $9,850,880 and $14,397,440 were fraudulently obtained. ARIN was able to uncover and revoke the addresses obtained through the fraud scheme following the arbitration [PDF] in the U.S. District Court for the Eastern District of Virginia, with the individual and the company behind the scheme being charged in federal court in a twenty-counts of wire fraud indictment.
Source: https://www.bleepingcomputer.com/news/security/over-757k-fraudulently-obtained-ipv4-addresses-revoked-by-arin/