''locking this thread as duplicate, please continue at [https://support.mozilla.org/en-US/questions/1045543 /questions/1045543]'' I was on a porn web site then all at once the screen filled up with a FBI telling me I have to pay $400 to unlock my browser. I tryed to exit but I couldn't the page just kept reloading. I had to cut the power to the PC in order to shut down then l deleted fire fox .