Re: how does host B know that its visitor is the one that visited host A?

On Tue, Aug 16, 2011 at 1:00 AM, Jonathan Rees <> wrote:
> It's possible that this is being used, but (a) Alan showed that there
> is no need to check the User-agent header; what I saw can be done with
> classical cookies and transclusion, (b) User-agent won't let the
> advertisers tell browser instances apart, since you could have
> multiple computers sending the same User-agent string on different
> computers, all with the same IP address (thanks to NAT). If an
> advertising service only checked User-agent it would have both
> imprecise targeting (decreasing the value of the service) and a much
> more serious privacy situation.

Thanks for the explanation. Sorry, that I missed you were talking
about browser instances and not browser vendors (that's what I thought
initially, while I wrote my previous mail).

Mukul Gandhi

Received on Wednesday, 17 August 2011 13:41:21 UTC