It said: "We the People of the United States" It is a platform for citizen engagement, http://www.whitehouse.gov/blog/2013/02/05/announcing-we-people-20-and-white-house-hackathon It is up to the court, when challenged to interpret whether it requires a citizenship. However, typical petitions are all related to public policies, elections and etc. In these cases, citizenship is required for signer. So go figure how you interpret it.