I have doubts about the harm/potential of a so called tracking cookie.
The problem is who decides what is a tracking cookie, what are the parameters that would make a cookie a tracking cookie.
Tracking Cookie: Any cookie that is shared among two or more web pages for the purpose of tracking a user's surfing history.
This is plainly overkill as there are many sites with third party cookies on then that aren't used for tracking purposed. From your link the threat/privacy risk is very low so.
Quantcast is the only open internet ratings service. We provide advertisers with audience profiles for millions of websites and services. We invite publishers to participate and demonstrate the unique value of their audiences. The service is free to everyone
Many of the anti-spyware mark tracking cookies as serious and that is absolute c**p they are of limited harm and no real security issue more a privacy issue if even that.