據說是灰色地帶，肯定是illegue。網上查的。

Legality

This is key. Ballstreams is indeed an “illegal” service. Their servers are located in Europe and could be shut down at any time due to the NBA taking them to court. It hasn’t happened yet, but this service is definitely grey market. If you’re at all concerned about legal issues, stick with NBA League Pass which is the official app.