Assassins:
John Wilkes Booth
John Hinckley Jr.
John Schrank (attempted to kill Teddy Roosevelt)
Serial Killers:
John Wayne Gacy
Paul John Knowles
John Allen Muhammad (DC Sniper terrorist)
John Edward Robinson (the Cyber Sex Killer)
Gerard John Schaefer (killed 34 women and girls in Florida)
Maniacs:
John Gotti
John Dillinger
John George Haigh (the UK's 'Acid Bath Murderer')
Just a short list for the wingnuts griping about "Hussein."