Accessing and downloading private databases without authorization can fall under various anti-hacking laws (like the CFAA in the US). Always ensure the directory you are accessing is a public repository intended for open use. How to Identify "High Quality" SQL Archives
If you find a directory that is explicitly public (such as a government or university open-data portal): index of databasesqlzip1 high quality
If you are managing databases, keep these "high quality" practices in mind: Disable Directory Listing index of databasesqlzip1 high quality