[William McKinley]

If I am not mistaken, no one ever took 'credit' for the Cole bombing. That was still a terrorist act.

[AntiGuv]

See my post #47. And, although AQ never explicitly took 'credit' for the USS Cole, OBL did appear in one of his little videos praising the action and obliquely claiming responsibility. In every instance of AQ terrorism, there's been some sort of eventual acknowledgment of their involvement, even if it hasn't been spelled out.