Spanish police just busted a massive crypto scam, arresting five people accused of swindling over 5,000 victims out of a jaw-dropping $541 million. Europol says the investigation is still rolling, but this is a big step in cracking down on what looks like one of Europe’s largest crypto fraud cases yet.

Editor’s Note: Crypto scams keep getting bolder, and this case shows how international law enforcement is scrambling to keep up. For everyday investors, it’s a stark reminder that if something sounds too good to be true in crypto-land, it probably is—and regulators are (slowly) catching up to the bad guys.