Wordpress by itself stores the call, email and url of the commenters into cookies (comment_author_).
This has the advantage that Wordpress will keep in mind your frequent commenters statistics and constantly have it completed after they return in your weblog, without your site visitors having to register.
Unluckily this additionally breaks most caching mechanisms (Varnish, Caching Plugins and so forth.) in that the server will must receive the comment_author_ cookies so as to properly autocomplete the records.
One manner to repair that is to have the server (or your caching plugin/server) automatically discard the ones type of cookies, however this could deliver down the engagement of your traffic (they will remark much less if they have to complete their name, electronic mail