For privacy's sake I won't link to the story, which is not hard to find since the Channel Tunnel doesn't get closed that often, particularly over bomb scares, and I will delete/edit this post if the poster wants, but wow:

    The bomb went undetected as he travelled back to the
    UK through the Tunnel but later, as he attempted to 
    return to France to show the device to a war expert 
    friend, he was stopped for a routine check.