

A St. Louis company managing prescription benefits of 50 million people said Thursday it called the FBI to investigate an extortion plot threatening to expose personal information, including prescriptions, of millions of its clients.

Express Scripts said it has received an anonymous letter containing the names of some 75 clients that includes dates of birth, Social Security numbers and their prescriptions. The letter threatens to expose millions of patient records if Express Scripts does not pay an undisclosed amount of money.

"We are cooperating with the FBI and are committed to doing what we can to protect our members' personal information and to track down the person or persons responsible for this criminal act," George Paz, the company's president, said in a statement.

Paz added that, "as security experts know, no data system is completely invulnerable."

The company said it has informed the 75 people whose data was breached, and has set up a website, esisupports.com to assist members.

The announcement comes shortly after three New Yorkers pleaded guilty to using hacked Citibank ATM card numbers and

PINs to steal $2 million from customer accounts.

Express Scripts said it received the letter in "early" October and is "unaware at this time of any actual misuse of any members’ information."