I tend to nit pic: so here goes.
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-- appear to promote the use of firearms;
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Does this mean no advertising for any future Olympic games or Pan American games?
Does this mean they won't run ads for police recruits?
And of course I'm sure they don't run ads for the armed forces by definition.
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-- be clearly defamatory;
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So vaguely defamatory is okay? As in: "Does Al Gore's wife know he's stupid?"