More specifically, you can send the gift but the people will not be able to redeem them. They end up stuck with a useless email. What you can do is send iTunes gift cards. These can be sent electronically and can be purchased for one country's specific store, in your case USA, from another country.
A passport is a travel document, usually issued by a country 's government, that certifies the identity and nationality of its holder for the purpose of international travel.Standard passports contain the holder's name, place and date of birth, photograph, signature, and other identifying information. passport is a document certifying identity and nationality; having the document does not of itself grant any rights, such as protection by the consulate of the issuing country, although it may indicate that the holder has such rights.
For many country pairs, a passport alone is insufficient and must contain a visa issued by the destination country. Neither passport nor visas guarantee entry into a foreign country -this is always ultimately subject to the discretion of the immigration officer at the border. Even if you do not travel, passports can be used in your home country as evidence of your identity.