Using these tools involves using stolen data. Accessing accounts that do not belong to you is a violation of the Computer Fraud and Abuse Act (CFAA) in the US and similar laws globally. Account Bans:
Github hosts various repositories that offer Netflix account checking tools, scripts, or APIs. These repositories usually provide instructions on how to use the tool, along with the source code. Some popular repositories may have multiple forks, indicating that the tool has been shared and modified by others. Netflix Account Checker Github