The public directory that contains information about who has registered every domain on the web looks increasingly at risk of going dark next month, after European data protection regulators rejected a proposal to make it compliant with the EU’s new privacy law.

The WHOIS directory is relied upon by many intellectual property and cybersecurity attorneys, as well as law enforcement authorities, as a tool to help fight infringement and track malicious activity online. Some say its demise or fragmentation would make doing so significantly harder.