Google FLoC

The evil empire known as Google is experimenting with yet another clusterfuck of a technology, known as FLoC (Federated Learning of Cohorts) - which is basically a technique to track visitors on the web, without the requirement of cookies. The Electronic Frontier Foundation explains pretty well why it is terrible.

In the current implementation, Chrome users can disable partaking in the experiment by disabling third party cookies (not just in Incognito, but enabling third party cookies in general). Moreover, server and website operators can disable FLoC by adding a header to the response. I've 'misused' my SysOp hat and rolled it out over several hundreds server - thereby effectively adding it to thousands of websites. If you operate a webserver or website I recommend doing the same. Here is how you can add the header to a number of different configs:

Relayd

If you are using relayd, you can add the following line to the http protocol section:

match response header set "Permissions-Policy" value "interest-cohort=()"

Nginx

For nginx the following line can be either set serverwide or in the server {} context:

add_header Permissions-Policy "interest-cohort=()" always;

lighttpd

setenv.add-response-header += (
  "Permissions-Policy" => "interest-cohort=()" 
)

HAproxy

Add the following line and reload HAproxy:

http-response set-header Permissions-Policy interest-cohort=()

rocket-nginx

Open /etc/nginx/rocket-nginx/rocket-nginx.ini with your favorite text editor, scroll down to line 43 and insert the following line:

http_header[Permissions-Policy] = "interest-cohort=()"

Run the parser (php rocket-parser.php) and restart nginx.

Apache httpd

With Apache httpd, the following lines can be set in the .htaccess file in the document root - or add it to the serverwide context:

<IfModule mod_headers.c>
    Header always set Permissions-Policy "interest-cohort=()"
</IfModule>