Can cookies be retrieved by a site that didn't set them?
I understand that there are plenty of options and tools to stop cookies from being set, or to delete them automatically, and maybe I don't understand some fundamental of how cookies function, but it seems like the current problem in privacy is sites tracking what I do when I am not on their site. As I understand it, this sounds like a site can retrieve cookie information set by another site that it isn't even associated with. Is this correct? Is that somehow a necessary function of websites? Is there a way to prevent that? I've always assumed that blocking the cookie set by an ad company will block the company from tracking me, but the tracking by facebook that everyone is talking about seems different. I can't find reference to a particular cookie that I could just block and forget about. It sounds like they're hoovering up everyone else's cookies, and that seems awfully strange.
Alla svar (3)
http://www.mozilla.org/en-US/lightbeam/
Beyond that please see this Google search for How do cookies work?
You can allow third-party cookies only from visited domains.
- Tools > Options > Privacy > Firefox will: "Use custom settings for history"
You can set the network.cookie.thirdparty.sessionOnly pref to true on the about:config page to have third-party cookies behave as session cookies that expire when Firefox is closed.
Ok, so according to the google page, cookies can only be retrieved by the sites that set them. Thanks. I regularly block third party cookies anyway.
So, the current hype about facebook tracking outside facebook isn't a new beast at all, I guess.