If you want a “scary computer prank” without impersonating law enforcement:
Real "FBI Lock" screens are often used in to extort money from people via gift cards or Bitcoin. To keep this a "solid story" and not a traumatizing event: Fake FBI Lock Warining Screen Prank
The prank typically involves displaying a full-screen image or a persistent browser pop-up that mimics the official and a stern legal warning. If you want a “scary computer prank” without
There are several reputable websites and apps designed for safe, non-malicious pranking: Department of Justice
: The FBI officially states that they never lock computers remotely or demand fines via digital screens.
: Turn off the internet to prevent further data exfiltration.
: High-resolution versions of the FBI seal , Department of Justice, or Cyber Crime Department.