It isn't quite as bad as it sounds. I'm sure PC only uses cookies for session ID and personal use...e.g. to remember/identify members, member personal settings etc.
The three I mentioned are third party tracking cookies, used for marketing or web analytics. There isn't supposed to be any personally identifiable information in cookies but I'm not sure how that can be. Google and Facebook are just about everywhere on the internet. If you have an acct with Gmail, Google+, or Facebook then it would seem that there is a very good possibility that personally identifiable info is is available through tracking cookies.
You can't get online without an IP, address and that is personally identifiable info, but your ISP should be the only party to be able to connect you personally to your IP addy.
I think the OP may have been referring to something else.
I'm not sure what the email campaign reference is about. When you buy something online you have to provide an email addy and you may be asked if you want to participate in email updates or promotions. If you're then contacted by email soliciting an update or a new product, and you respond using a link in the email, a cookie is going to show that there was a response from that email to help measure the effectiveness of the email campaign.
I don't think there is anything to worry about here at PC.
http://en.wikipedia.org/wiki/HTTP_cookie
http://www.google.com/intl/en/analytics/index.html

edit...I see now there were two clearer explanations given while I was tying all this paranoia