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Xfinity using WiFi signals in your house to detect motion

xfinity.com

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Re: Xfinity using WiFi signals in your house to detect motion

#131

Post by godshatter »

snarf21 wrote: post #47
jacobgkau wrote: post #2

> Subject to applicable law, Comcast may disclose information generated by your WiFi Motion to third parties without further notice to you in connection with any law enforcement investigation or proceeding, any dispute to which Comcast is a party, or pursuant to a court order or subpoena. Sounds like, at least in some limited circumstances (using the provided WiFi AP, having this feature turned on, etc), ISPs are goi…

Curious: What about adding a small battery powered WiFi device to your dogs collar? Would that look like a person moving around the house? What about a WiFi controlled mini drone that flew around you house? [Note: this should be illegal]

I was thinking of attaching a wifi enabled device to a roomba if you wanted to appear to be home when you weren't. I would hope, though, that doing something like this wouldn't be illegal. It's your home, your stuff, etc. Besides, I don't want to get arrested for leaving a rotating fan on or something.

Re: Xfinity using WiFi signals in your house to detect motion

#133

Post by matthew-wegner »

dylan604 wrote: post #34
josho wrote: post #29

Earlier quoted context omitted.

The solution here shouldn't be technical; it should be legal. If we rely on the technical path, Comcast can achieve the same by how many active IPv6 addresses are in use. Even if you aren't using your phone, the device is going to be constantly pinging services like email, and your ISP can use that to piece together how many people are at home. If we rely on legal protection, then not only Comcast, but all ISPs will…

What if I left my device at home?

It would work even better. From the linked support page:

"Motion is detected based on the amount of signal disruption taking place between the Xfinity Gateway and your selected WiFi-connected devices, so motion from small pets (around 40 pounds or less) can be filtered out while keeping you notified of large movements more likely to be caused by humans."

Re: Xfinity using WiFi signals in your house to detect motion

#134

Post by lrvick »

jacobgkau wrote: post #2

> Subject to applicable law, Comcast may disclose information generated by your WiFi Motion to third parties without further notice to you in connection with any law enforcement investigation or proceeding, any dispute to which Comcast is a party, or pursuant to a court order or subpoena. Sounds like, at least in some limited circumstances (using the provided WiFi AP, having this feature turned on, etc), ISPs are goi…

Comcast has remote control of all of their equipment so they will just turn it on for you if they get a court order or a big enough check from an adtech company.

Wifi imaging is a bit like a silhouette and generally accurate enough to work out gait and height which could give a good indication of which people are in what locations in a home. That is some very scary power in the hands of a corpo.

Re: Xfinity using WiFi signals in your house to detect motion

#135

Post by lrvick »

puppycodes wrote: post #129
vel0city wrote: post #112

Earlier quoted context omitted.

This technology doesn't rely on you actually having a WiFi device on you. It can detect presence/motion by changes to the standing waves of the EM propagation throughout the room. As the salty water meatbags move from room to room we change how the reflections and scattering patterns of 2.4 and 5GHz waves move. Studying these changes and some calibration, you can even determine small changes (like is the person on th…

im very skeptical of the accuracy claimed. The layout and complexity of objects in most homes to do this is way to awkward to work reliably. For someone breathing or a heartbeat you need much higher GHz signal. Usually this is done at 30ghz to 60ghz. The power flux leaving the antenna has an inverse square drop off rate which makes this basically impractical unless your standing directly in front of it.

I have personally tested wifi imaging from a cheap old 2.4Ghz linksys router that was accurate enough to tell if my hand was open or closed, maybe 10 years ago.

Re: Xfinity using WiFi signals in your house to detect motion

#136

Post by lrvick »

jhowison wrote: post #124
timewizard wrote: post #35

Earlier quoted context omitted.

You can turn the customer AP off; however, the Comcast Customer Shared WiFi is always on. This is true even for Comcast Business accounts. You're expected to be a hotspot for their other customers. Which is one of the main reasons I bought my own modem.

You can turn off the shared hotspot: https://www.xfinity.com/support/articles/disable-xfinity-wif...

And they can turn it right back on again.

Re: Xfinity using WiFi signals in your house to detect motion

#137

Post by brewtide »

snarf21 wrote: post #47
jacobgkau wrote: post #2

> Subject to applicable law, Comcast may disclose information generated by your WiFi Motion to third parties without further notice to you in connection with any law enforcement investigation or proceeding, any dispute to which Comcast is a party, or pursuant to a court order or subpoena. Sounds like, at least in some limited circumstances (using the provided WiFi AP, having this feature turned on, etc), ISPs are goi…

Curious: What about adding a small battery powered WiFi device to your dogs collar? Would that look like a person moving around the house? What about a WiFi controlled mini drone that flew around you house? [Note: this should be illegal]

It's basically passive radar using the wifi bands as the reflection AFAIK. It doesn't seem to be about the active state of devices, but the deflections in known points. It's creepy.

Re: Xfinity using WiFi signals in your house to detect motion

#138

Post by aaronmdjones »

harles wrote: post #116
zeta0134 wrote: post #109

Earlier quoted context omitted.

This practice, and fear of the exact sort of nonsense in this article, plus wanting to keep my wifi bandwidth free for the network I actually connect to, is why I'm still on AT&T DSL in my area, at 50 mbps. Comcast is available at up to gigabit, and they can keep it.

AT&T is pretty bad in its own way. They snoop DNS and to sell your info (including physical address) to advertisers - even if you switch your DNS providers. They used to had a paid opt out (~$20/mo IIRC) but I don’t see that option anymore.

This is quite easy to avoid by using DNS over TLS. It's like 15 minutes of effort in some OpenWRT documentation [1]. If you want any hope of having some semblance of control and privacy, you would already be using your own router, with their CPE being relegated to modem-only duties. It only makes sense that in this situation you choose a router that can run highly-configurable and privacy-preserving software.

I did it several months ago, including the optional adding an outbound firewall rule dropping forwarded UDP/TCP 53 traffic (I tried the redirect rule suggested there first, but it didn't work and the firewall ruleset failed to load, so a drop will have to do. I didn't bother investigating why, because everything on my LANs is configured to use the router as their only nameserver anyway).

I also added a rule dropping it from the router itself in case something breaks, for example if it suddenly decides to start honouring the DHCP-received nameserver addresses (my ISP) despite being configured not to.

EDIT: The article doesn't make this clear, but the bootstrap section is only necessary if you specify upstream nameservers by name (e.g. "https://dns.cloudflare.com/dns-query"). This is not required. For example, you can configure a manual upstream of "tls://1.1.1.1" like I did, and then it doesn't need to do any DNS lookups at all, so does not need to be configured with bootstrap servers, so will not break if you add the 2 firewall rules I mentioned.

[1] https://openwrt.org/docs/guide-user/services/dns/dot_dnsmasq...

Re: Xfinity using WiFi signals in your house to detect motion

#139

Post by snickerbockers »

Okay I'm as concerned about privasy as everybody else is here but i also gotta admire that its pretty neat they can actually do that. Are they measuring the signal echo like what radar does? If they controlled both the receiver and transmitter i wouldn't be as surprised to find out they can tell when something crosses between them and form a 2-dimensional mesh (like that episode of Star Trek TNG where geordie detects cloaked romulan ships by having starfleet deploy a fleet of ships that send signals back and forth and look for timing variances) but if I'm understanding correctly this is different because they only control a single point in the network?

I wonder if they have enough information to make out shapes or if it's just a simple rangefinder?

Re: Xfinity using WiFi signals in your house to detect motion

#140

Post by slt2021 »

josho wrote: post #29
jacobgkau wrote: post #2

> Subject to applicable law, Comcast may disclose information generated by your WiFi Motion to third parties without further notice to you in connection with any law enforcement investigation or proceeding, any dispute to which Comcast is a party, or pursuant to a court order or subpoena. Sounds like, at least in some limited circumstances (using the provided WiFi AP, having this feature turned on, etc), ISPs are goi…

The solution here shouldn't be technical; it should be legal. If we rely on the technical path, Comcast can achieve the same by how many active IPv6 addresses are in use. Even if you aren't using your phone, the device is going to be constantly pinging services like email, and your ISP can use that to piece together how many people are at home. If we rely on legal protection, then not only Comcast, but all ISPs will…

just buy your own simple modem and install your own wireless access point.

do not buy any device from comcast you dont fully control!

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