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I don't get it. A much more accurate sensor for detecting human movement is a camera.

by guelo 10y ago

yannyu 10y ago
Last I checked, most cameras can't see through walls. "Something in the way? No problem. A pair of MIT researchers wrote in 2013 that they could use a router to detect the number of humans in a room and identify some basic arm gestures, even through a wall. They could tell how many people were in a room from behind a solid wooden door, a 6-inch hollow wall supported by steel beams, or an 8-inch concrete wall—and detect messages drawn in the air from a distance of five meters (but still in another room) with 100 percent accuracy. (Using more precise sensors, the same MIT researchers went on to develop systems that can distinguish between different people standing behind walls, and remotely monitor breathing and heart rates with 99 percent accuracy."
- guelo 10y ago
  If you look at that paper you'll see they use some custom machine on the other side of the wall to send and sense the wifi signals. And all they get is relative movement away or towards the machine. I'm sure an infrared camera would be much more accurate. Doesn't seem practical at all.
JoelBennett 10y ago
But how well do cameras work through walls? Like Bart Simpson said "No one suspects the butterfly." In this case, no one would suspect their router to be watching where they physically are. Imagine a SWAT team being able to detect where people are within a room before they enter the place - all by snooping through a router.
- imron 10y ago
  And they don't even need to snoop through your router. They could bring their own and just place it outside the door.
  - rrobukef 10y ago
    They also don't need to bring a router, just a special microwave.
roywiggins 10y ago
Everyone has a WiFi router in their home. Webcams give you great data in a particular frame, but laptops aren't always open, they move around, they only look in one direction at a time. WiFi routers just look like passive boxes. Heck, in an unfamiliar house you might have to go on an expedition to even find the thing, and a router shoved behind a cabinet can track you too.
ww520 10y ago
Line of sight, or the lack of. Pretty soon the cell phone in my pocket can use its wifi to detect the pins you typed on the ATM terminal. Wifi jammer will be popular.
peterkelly 10y ago
I think the point of the article is that there is potential for Wifi routers to be used to monitor people without their knowledge. An attacker could potentially penetrate your router and install malicious code on it to monitor certain things, where it would be too obvious/not viable for them to put a camera in the room. (and also the walls thing that others have mentioned)
- imron 10y ago
  And you might not even need to penetrate the router. Sitting here at home (in an apartment building), I can currently count 5 Wifi networks to connect to, and only one of them is mine.

I don't get it. A much more accurate sensor for detecting human movement is a camera.

by guelo 10y ago

I don't get it. A much more accurate sensor for detecting human movement is a camera.

Last I checked, most cameras can't see through walls. "Something in the way? No problem. A pair of MIT researchers wrote in 2013 that they could use a router to detect the number of humans in a room and identify some basic arm gestures, even through a wall. They could tell how many people were in a room from behind a solid wooden door, a 6-inch hollow wall supported by steel beams, or an 8-inch concrete wall—and detect messages drawn in the air from a distance of five meters (but still in another room) with 100 percent accuracy. (Using more precise sensors, the same MIT researchers went on to develop systems that can distinguish between different people standing behind walls, and remotely monitor breathing and heart rates with 99 percent accuracy."

guelo 10y ago
If you look at that paper you'll see they use some custom machine on the other side of the wall to send and sense the wifi signals. And all they get is relative movement away or towards the machine. I'm sure an infrared camera would be much more accurate. Doesn't seem practical at all.

JoelBennett 10y ago

But how well do cameras work through walls? Like Bart Simpson said "No one suspects the butterfly." In this case, no one would suspect their router to be watching where they physically are. Imagine a SWAT team being able to detect where people are within a room before they enter the place - all by snooping through a router.

imron 10y ago
And they don't even need to snoop through your router. They could bring their own and just place it outside the door.
- rrobukef 10y ago
  They also don't need to bring a router, just a special microwave.

roywiggins 10y ago

Everyone has a WiFi router in their home. Webcams give you great data in a particular frame, but laptops aren't always open, they move around, they only look in one direction at a time. WiFi routers just look like passive boxes. Heck, in an unfamiliar house you might have to go on an expedition to even find the thing, and a router shoved behind a cabinet can track you too.

ww520 10y ago

Line of sight, or the lack of. Pretty soon the cell phone in my pocket can use its wifi to detect the pins you typed on the ATM terminal. Wifi jammer will be popular.

peterkelly 10y ago

I think the point of the article is that there is potential for Wifi routers to be used to monitor people without their knowledge. An attacker could potentially penetrate your router and install malicious code on it to monitor certain things, where it would be too obvious/not viable for them to put a camera in the room. (and also the walls thing that others have mentioned)

imron 10y ago
And you might not even need to penetrate the router. Sitting here at home (in an apartment building), I can currently count 5 Wifi networks to connect to, and only one of them is mine.