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    Re: Units in Navigation
    From: Frank Reed
    Date: 2020 Sep 26, 12:17 -0700

    David P, you wrote:
    "Great.  The problem is when you scroll down a bit further it also tells you where you're asking from."

    What? No it doesn't! Not on my computer. But of course, if you clicked on one of the endless website returned by that search, you may well have found one that uses your location. Many do, and this is completely normal on the internet (more below). All I was pointing to was the standard unit conversion capability built right into Google's search function. Rather than sending you to some random website to do a conversion, Google's services do the conversion directly based on the question, right at the top. You ask it,  what is 15000 feet in meters? Or 28.90 in Hg in kPaand it comes back with the answer straight away, including a small tool that lets you try different values, and a nice hint on a general conversion formula. That's direct from Google, which is quite different from a traditional internet search.

    As for your follow-up comment:
    "Thus adding truth to the term 'We know where you live'.  Creepy' and too clever by half."

    All I can say, is the internet has known where you are, to a considerable extent, since the internet first launched (not always, but in most circumstances). Time for a primer on modern device "location services", I think...

    Without even getting "close to the metal", apps on modern devices have access to "location services" in most modern operating systems. Apps can be written which can access that information on day one of a programming class. Some of these services require user permission, by law in most countries, and specifically when using high-accuracy location, for privacy and to prevent criminal stalking. So your device will not usually make your GPS position available to an app (or website) unless you, the end-user, allow it. For example, if you visit my USNO clone, it will fill in your current location, but you have to allow that manually. If you don't, you lose functionality, but you can always type in your location instead. If exact location is denied by the end-user, I could also get very close in many cases using other tools (especially an IP lookup, see below), but I get no benefit from that so I haven't bothered to implement it.

    Devices can also determine location to relatively high accuracy using WiFi signals. This was quite ingenious when it was first invented and employed by smartphones as a substitute for GPS in the early days. Those "early days" are fully within the history of the NavList community, and I can recall discussing this when it first appeared (c.2007), but I don't have time to go digging for those old posts. The idea is that home WiFi signals can be recorded and mapped by purpose-built receivers on roaming vehicles and also by users just walking around. Note that this is not about accessing the WiFi or getting on someone else's WiFi. It's just the basic "presence" of the WiFi signal and the way that the intensity falls off with distance that allows them to function for position-finding. 

    Next up is the oldest technology: the user's IP or "Internet Protocol" address. These can be local addresses, like a set of numbers defining your printer on your home network, but more significantly they are global numbers that uniquely determine each device's network connection location. Without these addresses, the internet can't send you data. In most cases, but by no means all, these addresses can be geo-located. That is, an IP address corresponds to a physical street address which can be looked up automatically online and converted to a latitude and longitude automatically. Nearly all websites and services since you first got online have recorded your IP address from the moment you arrived. 

    Try this: open an email in "raw" mode where you can see the "headers". Just now I looked at an email, spotted something labeled "client-ip" with a value of "". This string of numbers is an IP address. We can find out quite a bit about it by visiting any one of thousands of sites that will look up an ip address. Here's one: https://extreme-ip-lookup.com/ Like many IP lookup sites, this one provides geolocation and shows us a spot on a map that is in some sense "close to" the device that sent that email (in this case, Mountain View, CA which means it's Google, but the dot on the map is not exactly Google's front door. This is normal functionality on the internet. Your location is not merely "traceable", it is often public. And for home users connected by cable or wire, the conversion of the IP address to physical location is often exact right down to the street address. It's been this way for decades.

    So how do we circumvent this location-fixing trap? How can you hide? 

    Not all internet services display correct location information. Some are one-step removed from the end-user's device. The best example of this is the IP address supplied by a mobile phone. Mobile phones usually get their addresses when booted up from a pool of addresses. Some release and re-acquire an IP on a regular basis, every few minutes. You can test this easily by visiting one of those lookup sites. Hit this link, https://extreme-ip-lookup.com/, on your home internet, and then try it again on your mobile phone (but not when using your home WiFi on the mobile device). When I do this, my cable internet service (which I only acquired at the beginning of April because I needed to pay up for more bandwidth to teach online classes) yields an IP-based location that's within a few thousand feet of my true position while my phone yields a location which bounces around anywhere from Boston to New Jersey and various points in between. Of course, there is still a direct one-to-one connection through the internet to the physical endpoint, and the service provider can track it (and so can other parties with minimal legal access), but the physical address is at least not publicly visible in most cases when you're on a smartphone or similar mobile device.

    Many internet services use your IP-based location to decide what they will show you. This has come up occasionally in NavList discussions. For example, if someone posts a link to an interesting BBC video, an American NavList member may respond that they can't watch it. The servers of the BBC are checking IP address locations and blocking non-UK users. This sort of regional sorting can be defeated (at a price if you want reasonable bandwidth) using a VPN service which routes your internet traffic through a different set of servers located in another country. There are also devices called "seedboxes" which are minimalist computers (just a motherboard in a wall, no monitor or any other interface) rented for a small fee in other countries that perform a similar task. That's how millions of people around the globe still access services like thepir---bay without threat of being tracked by IP.

    Finally, if you think you can hide once you have learned how to use a VPN or by using a "seedbox", think again! Web-based advertisers and other actors figured out years ago that almost any user can be fingerprinted within some limits based on the unique characteristics of each and every device. There are many articles on this topic. Here's one from a couple of years ago: this-is-your-digital-fingerprint. This is the sort of thing that you should worry about. It's potentially dangerous since unsecured databases are tracking you all the time, and these databases can easily be stolen and used for all sorts of criminal purposes from simple extortion to the destruction of democracy. This is where you should worry! Your latitude and longitude have been available for decades. It's your identity that's under threat today.

    Frank Reed
    Clockwork Mapping / ReedNavigation.com
    Conanicut Island USA

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