A former DEA official and their elaborate scam resulted in fraud worth millions of dollars. He convinced over 12 companies that they would eventually be reimbursed by the CIA and he ended up scamming them of over 4.4 million dollars, he admitted in Federal Court. He managed to get the companies to communicate using encrypted communication and he worked under false government positions. He even had them sign non-disclosure agreements and accused them of leaking classified information. He is currently facing a 20-year sentence.

Source: By Nick Youngson - http://www.nyphotographic.com/Alpha Stock Images - http://alphastockimages.com/ - http://creative-commons-images.com/clipboard/fraud.html, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=70444837