What's new re Web bugs

[ravi]

Chris Burford wrote:
> 
> What was new for me in the Yahoo scare was that web bugs can track your
> contact with *all* web sites and not just the one from which you
> catch/accept the bug.
> <...>
> Even under the libertarian principle of informed consent, we usually get
> asked by responsible lists whether we object to our names being given to
> commercial companies. The alarm signalled by the user of Yahoo which I
> quoted, is that she found nothing like a process of informed consent
> about the fact that the innocently named "web beacon" would be
> potentially gathering information about *all* her commercially
> significant use of the internet throughout its length and breadth.
> <...> 
> So if you are carrying one of these little web beacons every time you
> visit Lou Proyect's Marxism site this marks you out as a targetted
> member of a sub group, with possible security relevance. (Remember the
> software is specifically interested in profiling subgroups.)
> 

i do not see technically how the sort of tracking you suggest would be
feasible, apart from relying on broken/buggy referrer headers in early
versions of netscape/explorer. there may be security holes in the
javascript [sandbox model] security that a script could potentially
exploit to track your activities after you have left the site. i have
not heard of any such exploits. i definitely do not see how an invisible
gif along with cookies on one site can follow me around to another site,
unless the second site co-operates.

any further links where i might update my knowledge, would be useful!

	--ravi