Amex doesn't, I've used AMEX to purchase all but one of my firearms, never been refused. PayPal has their own policies, never used them so I can't confirm or deny the accusation. Comparing firearms to cakes is apt. Firearms can be denied any person failing a background check, but are not denied any person based on religion, gender, sexual orientation, or political beliefs. Excellent support of the people who were denied services by a baker.