It's not just for Americans!
Marcus and Maddy from LittleBird have gotten their "Ninja Blocks" project funded,
From the kickstarter guidelines
To be eligible to start a Kickstarter project, you need to satisfy the requirements of Amazon Payments:
Be a US resident and at least 18 years of age with a social security number (or EIN), a US bank account, US address, US state-issued ID (driver’s license), and major US credit or debit card.
So I don't know how they did it.
Rob