The only cookie used is “newsletter” which contains the user id, used to unlock the content if the content locking feature is used. Data in the cookie is not used to profile the user but is like a session cookied to recognize the user, like the login cookie of wordpress.
I’m experiencing what appears to be a cookie related error with the newsletter locked content extension. I just updated the newsletter plugin to the latest version (5.8.2) from a version where before the locked content feature was broken out into its own extension. Everything was working properly before the update. Now when you go through the double-opt-in process of subscribing the new registration appears in the newsletter subscriber list but the locked content does not unlock. The content does unlock if you are logged into the wordpress backend.