In 2013, New Jersey legalized online casino gambling and poker. It was one of the first states to legalize them, and because of this, New Jersey helped the gambling industry expand even more due to its new virtual format.
Along with the geolocation requirements, all that's needed is that the person is a US resident, not necessarily belonging to the state of New Jersey, and is a minimum of 21 years of age. With no other options, some NY residents opt for this to play casino games legally.