Our requirement is that user should be Australian residents.
This requirement stems from requirement from Macquarie bank that you have a nexus to Australia - this means that you have a passport, student visa, work visa or similar permit which can prove your connection.
To get into the market, we've currently made Stake available to Australian residents only. If there's enough demand, we'll work on getting other jurisdictions up and running - like we have in NZ!
We'd love to take Stake into other markets, the same problem we're trying to solve exists in other markets.