I love a pure intellectual challenge like this...

An Achilles heel in the basic concept is that (as the patent is written; more later on alternatives) you would know when your computer is being targeted by the flurry of ping transmissions you'd be receiving. Further, each ping would carry the IP address of the beacon computer, allowing you to pretty efficiently reverse-engineer the network being used by Big Brother. IP-spoofing, putting a false address in the sender field of the packets, couldn't be used, because the response to the ping has to be able to be routed back to the beacon; IP-spoofing is only useful for one-way transactions like sending email.

Having mapped out the attacking network, you can make your own estimates of latency times. You wouldn't have to create a map of the entire network (your point #3), but just the part that's actually connecting you to the beacons. Based on that, you could intelligently adapt your ping response delays to apparently shift your location elsewhere on the Net.

Their countermeasure to you varying your ping response times is to use traceroute rather than a single ping. Traceroute returns the time to each intermediate node in the packet's journey, so a long or varying delay at the final hop--to your computer--would show up as an anomaly. Traceroute would thus limit your wiggle room to within the region defined by the second-to-last nodes and their latency times.

Disabling ping on your computer, for the same reason, still allows them to get your general area from the penultimate nodes.

So, (thinking aloud as I go), you could blur your position somewhat by playing with ping times, but it's a very limited cloak of invisibility.

But I'm supposed to think like a Hacker...so, how about I write a virus that goes around and surreptitiously installs proxies all around the world. Then I'd have such a wealth of proxies that I could rotate randomly through them like one of those spread-spectrum radios.

Or, just a thought, instead of spreading the virus surreptitiously, I might go public and appeal for all people concerned about privacy to voluntarily download the proxy software and participate in a countermeasure network that would benefit all participants. Kind of an open-source + peer-to-peer approach.

If my viral proxies are also equipped with latency-measuring capabilities, their data can be used to build an even more refined view of the attacking network. With that info you could construct a pattern of proxy use, plus some fine-tuning of ping times, to spoof the surveillance system into believing you're at a particular false location. You could force advertisers using this technology to waste their money targeting you based on false information.

The patent talks about pings, which is a defined Internet protocol, which means that all the above applies--you know when you're being pinged.

But the latency time of other packets in other protocols can be measured too. As I speculated originally, you could construct a Web page with graphics from many different sites, and you could measure the latency on each of the transactions. Script on the Web page could increase accuracy by profiling the host computer's speed, and profiling the time to load graphics files of known size. The script can report all that back to a central site by creating and submitting a hidden form.

Not using the known ping protocol would make it harder to detect this kind of attack. The defensive software would have to be more sophisticated, and sniff incoming Web pages for the suspect pattern of page resources pulled from many different sites. There'd be a lot of false positives, though, since that's a common pattern on a lot of Web pages (e.g. space enthusiasts, who love to weigh down their pages with images culled from all over the Net). The challenge is a bit like identifying spammers, which requires a lot of people feeding data into a central system that looks for global patterns.

Just some musings...this looks like a tough system to beat, but it's not hopeless.