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London garden bridge users to have mobile phone signals tracked

theguardian.com

101–110 of 114 posts

Re: London garden bridge users to have mobile phone signals tracked

#101

I did a talk on privacy topics from a user's perspective at a small 'tech fair' this weekend and I was delighted to see this tweet showing a map of the venue showing everyone's precise location: https://twitter.com/johnebridge/status/662984007370612736 I was able to add it to the slide deck just in time and people were genuinely surprised by it. It's a good thing that the company were transparent about it and shared…

Can you share more around how that map was generated?

Re: London garden bridge users to have mobile phone signals tracked

#103
post #9

That's why Richard Stallman correctly described mobile phones as tracking and surveillance devices: > https://stallman.org/rms-lifestyle.html "Cell phones are tracking and surveillance devices. They all enable the phone system to record where the user goes, and many (perhaps all) can be remotely converted into listening devices."

The small educational centre where I teach has recently provided free wifi to users of the building. It is a good connection. You have to give a mobile phone number once to use the system. This morning, I went in with my old Thinkpad on which I have replaced Xubuntu with Slackware/MLED including a complete reformat and encryption of the SSD. The wifi recognised the machine and greeted me by name. I can only assume th…

> You have to give a mobile phone number once to use the system.

I encountered this problem in Dublin airport a few years ago, before they switched to a different wifi provider.

The authentication code to join the wifi network would be sent by SMS. Which seems clever, until you realise that many people transiting Dublin won't have international roaming ( I didn't ) so can't receive the SMS.

Re: London garden bridge users to have mobile phone signals tracked

#104

I did a talk on privacy topics from a user's perspective at a small 'tech fair' this weekend and I was delighted to see this tweet showing a map of the venue showing everyone's precise location: https://twitter.com/johnebridge/status/662984007370612736 I was able to add it to the slide deck just in time and people were genuinely surprised by it. It's a good thing that the company were transparent about it and shared…

Can you share more around how that map was generated?

I have no idea, sorry. I just happened to see it when someone else re-tweeted it and it looked perfect.

The service was provided by JT Global (website here: http://www.jtglobal.com/jersey/) and Purple WiFi (http://www.purplewifi.net/) so you might try following up with them? I don't know any of the people involved, I just showed up for my talk and left soon after.

Re: London garden bridge users to have mobile phone signals tracked

#105

Earlier quoted context omitted.

The small educational centre where I teach has recently provided free wifi to users of the building. It is a good connection. You have to give a mobile phone number once to use the system. This morning, I went in with my old Thinkpad on which I have replaced Xubuntu with Slackware/MLED including a complete reformat and encryption of the SSD. The wifi recognised the machine and greeted me by name. I can only assume th…

Why do machines broadcast MAC addresses to networks? to identify themselves? Is it easy to randomize your MAC?

Yes, computers broadcast their MAC address when they first connect to a network so that they can, for example, obtain an IP address via DHCP. However the MAC address isn't forwarded beyond the LAN to which the computer is connected.

https://en.wikipedia.org/wiki/Address_Resolution_Protocol

Re: London garden bridge users to have mobile phone signals tracked

#106

I did a talk on privacy topics from a user's perspective at a small 'tech fair' this weekend and I was delighted to see this tweet showing a map of the venue showing everyone's precise location: https://twitter.com/johnebridge/status/662984007370612736 I was able to add it to the slide deck just in time and people were genuinely surprised by it. It's a good thing that the company were transparent about it and shared…

Can you share more around how that map was generated?

Not the original poster, but when you sign into a Wi-Fi network, the router needs to know where to send the packets, so it needs to have a way to identify your device. That's why all devices that can connect to a network have what's called a MAC address[1] – a very long number that is unique to your device. Your device also broadcasts that address when it scans for networks, so just about all the time. When you control several access points and a few of them see the same device at the same time, you can triangulate the location of that device down to a few metres.

The company I used to work for did something similar[2] at a conference over the course of three days. (You can drag on the map to highlight individual devices.) It's really cool and really quite creepy.

[1]: https://en.wikipedia.org/wiki/MAC_address

[2]: https://apps.opendatacity.de/relog/

Re: London garden bridge users to have mobile phone signals tracked

#107

Earlier quoted context omitted.

Can you share more around how that map was generated?

Not the original poster, but when you sign into a Wi-Fi network, the router needs to know where to send the packets, so it needs to have a way to identify your device. That's why all devices that can connect to a network have what's called a MAC address[1] – a very long number that is unique to your device. Your device also broadcasts that address when it scans for networks, so just about all the time. When you contr…

Really helpful, thanks for sharing.

Is disabling wifi when you are not connected sufficient to stop this sort of tracking?

Re: London garden bridge users to have mobile phone signals tracked

#108
post #9

That's why Richard Stallman correctly described mobile phones as tracking and surveillance devices: > https://stallman.org/rms-lifestyle.html "Cell phones are tracking and surveillance devices. They all enable the phone system to record where the user goes, and many (perhaps all) can be remotely converted into listening devices."

The small educational centre where I teach has recently provided free wifi to users of the building. It is a good connection. You have to give a mobile phone number once to use the system. This morning, I went in with my old Thinkpad on which I have replaced Xubuntu with Slackware/MLED including a complete reformat and encryption of the SSD. The wifi recognised the machine and greeted me by name. I can only assume th…

That will probably be the new normal.

When toll-free phone number services started providing number identification to the service in the 1980s, American Express had their system look up the customer's record from the phone number, and their operators started greeting customers by name. Some customers saw this as "creepy", and American Express stopped such greetings, although the customer's record was still looked up.

Today, everybody has caller ID and name lookup.

Re: London garden bridge users to have mobile phone signals tracked

#109

Earlier quoted context omitted.

The small educational centre where I teach has recently provided free wifi to users of the building. It is a good connection. You have to give a mobile phone number once to use the system. This morning, I went in with my old Thinkpad on which I have replaced Xubuntu with Slackware/MLED including a complete reformat and encryption of the SSD. The wifi recognised the machine and greeted me by name. I can only assume th…

Why do machines broadcast MAC addresses to networks? to identify themselves? Is it easy to randomize your MAC?

MAC addresses are part of the link layer of an Ethernet network. The same link layer segment of a network must have unique MAC addresses so that packets can be unambiguously routed to the correct destination. MAC addresses actually consist of two parts, one part is assigned to the manufacturer, the other part is basically a serial number that the manufacturer generates. So from looking at a MAC address, you can look up who manufactured the device. The MAC addresses are not broadcast beyond the layer 2 network segment that you're connected to. However, that does mean that anyone in range can read the MAC address of your wifi card as it is sent 'in the clear' (not encrypted). Generally MAC addresses are also used for access control (though this is not particularly effective as MAC addresses can be spoofed) and for long-term IP address assignments (same IP can be assigned on subsequent connections).

Re: London garden bridge users to have mobile phone signals tracked

#110

Earlier quoted context omitted.

Not the original poster, but when you sign into a Wi-Fi network, the router needs to know where to send the packets, so it needs to have a way to identify your device. That's why all devices that can connect to a network have what's called a MAC address[1] – a very long number that is unique to your device. Your device also broadcasts that address when it scans for networks, so just about all the time. When you contr…

Really helpful, thanks for sharing. Is disabling wifi when you are not connected sufficient to stop this sort of tracking?

I'm not an expert, but yes, when you disable Wi-Fi, your device will stop scanning for networks and broadcasting your MAC address, so you can no longer be tracked that way. More recently, phones have also started randomising MAC addresses while scanning (starting in iOS 8, I don't know about others), so you can only be tracked for a short time as long as your Wi-Fi is on but not connected.
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