The 1st amendment protects you from the government not the NFL. I'm pro-gun, but I honestly couldn't care less what ads the NFL allows and doesn't. It's not as if they're allowing a anti-gun ad while disallowing this one.
I have to say that I'm pretty impressed that the very first comment on this thread was to call out this common misunderstanding of the 1st Amendment. I'm not a big pro-gun guy myself, but I don't really like the NFL practicing this level of censorship of ads. Nonetheless, they are well within their constitutional rights as a private entity to do so.
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