The '__cfduid' cookie is set by the CloudFlare service to identify trusted web traffic. It does not correspond to any user id in the web application, nor does the cookie store any personally identifiable information.
For more information visit: https://support.cloudflare.com/hc/en-us/articles/200170156-What-does-the-CloudFlare-cfduid-cookie-do-
You may delete and block all cookies from this site, but please note that parts of the site may not work.
Most web browsers allow some control of most cookies through the browser settings. To find out more about cookies, including how to see what cookies have been set and how to manage and delete them, visit www.allaboutcookies.org.