(US) American Express called and said I had opened a new account and tried to buy child exploitation videos with it

The user received a call from American Express accusing them of opening a new account to purchase child exploitation videos. The credit card company filed a report with the FBI, leading to hours of calls and threats of criminal charges. The user hung up on an FBI agent in New York and later contacted their local FBI office, which advised them to call the number on their card, which appeared legitimate.