Take firstname.lastname@example.org is a fake FBI email invented by webscamers for money extorting purposes. Many users who recently encountered FBI moneypak virus or other related ransomware, e.g. Your Computer Has Been Locked by Department of Justice virus, have been presented this email to facilitate fulfilling the frauds. In fact, this email has nothing to do with FBI (Federal Bureau of Investigation) or the US Department of Justice. Instead, it comes as part of the most nasty virus that we categorize as ransomware, which may be commonly called as your computer/pc has been locked virus. Once such infection invades in, the computer desktop would be totally hijacked and display a fraudulent message on the PC screen to force victim users to pay a fine for false scaring reasons of all sorts to unlock the computer. If less aware, users would be fooled to pay but worse still, the further risk would be leak of sensitive data like credit card No. and passwords if such is the case. Hence, everyone should take proper caution on that.
You may see detailed information on specific ransomware popular on the Internet now and step by step removal guide is offered as well:
Your computer has been locked by Department of Justice (alias, Americana Dreams ransomware), Police Central e-crime Unite virus, FBI moneypak virus, Malex ransomware, United States Cyber Security Virus, I.P.A virus, Citadel Reveton, etc.
Good luck to you all and be safe online.