Netflix is experimenting with a method of preventing login exchange.

Popups from the successful streaming service have been asking certain users to “verify later” or “verify through email or text.” “If you don’t live with the owner of this account, you need your own account to keep watching,” the screen reads, according to Streamable.com, which first reported the test.

The test comes as more users exchange passwords and programs, as streaming services become more popular. Netflix acknowledged the survey but declined to specify how many participants were involved or whether it was just conducted in the United States.

The potential crackdown has ramifications that go beyond password sharing. It’s an account authentication test, but it may be used for protection or anti-fraud purposes as well. Netflix is known for running hundreds of A/B experiments per year for its more than 200 million worldwide users, as well as a diverse set of product capabilities and monetization platforms.