In many places just taking a simple walk can be a dangerous activity due to violence, harassment or other acts that may lead to injuries, accidents or even traumas. One specific group of people that suffers due to not safe streets are women: many of them feels unsafe and often must deal with situations where they feel that they are being followed.

One possible approach to make street walkers safe is to somehow send a message to someone, generally calling for help, or taking another action such as cross the street, walk/run faster, or fetch a protective device (i.e. taser, pepper spray). From the technology point of view, there are many apps and wearable devices that provide a panic button functionality with many options to alert or notify someone of the situation with important data, such as GPS coordinates. However, current “panic button” solutions are activated only after the person that feels the threat suspects or know what is happening, which sometimes is too late.


To gather more information about this situation and understand better the point of view of someone who is being followed in the street (or have the feeling of being followed) I did some interviews with a couple of women, including my wife. Unfortunately, this situation is more common that I was aware of, which makes me a little bit sad because of what a lot of women went through. This kind of situation make me eager to think about something that I could do.

First, I asked if the interviewed had ever of being followed or feel that was being followed. Many of the ladies that I talked confirmed that it happens a lot, mostly on streets and at night. The ladies mentioned that in these scenarios it is common to give a fast look over the shoulder to take a sneak peek at what is happening behind them and try to spot someone that is approaching from behind of even following them from a distance. Furthermore, they reported that they try to be discrete in their actions to avoid the follower to note their suspicions. Also, the stories they told are full of fear and panic if they found that the follower realize they are a possible victim. Another common attitude is to not use the mobile (fear to show any valuable item that could raise the interest for a mug) or any other gesture that signals their apprehension.


Based on the interviews I started to think of a possible design solution to help someone that feels to be followed in a suspicion’s way. I also remembered that the 2021 Hackaday prize had a category for hardware design solutions that involve displays. Therefore, I started thinking about the design of the solution that somehow involves displays and can help the in the “felling of being followed” situation.

During the initial design I thought about some spy movies where the main protagonist has the feeling of being followed. In these scenes it is common to see that the spy uses a mirror, a storefront glass, or any other reflective surface to look behind and note that some bad guys are looking and following him/her. We also have similar scenes in movies were cops are trying to do unsuspicious surveillance, most of the time inside a car eating donuts and drinking coffee.

One of the references that came to my mind was the rear camera that a some of cars have. They provide a helpful visualization when parking and some of them have proximity sensors and virtual bars to help the driver see the boundaries of the parking space fitted to the car size.

After some research I did some sketches and come up with a solution: a rear view camera that the women would wear as a wearable to help see from behind and be aware of a possible suspect following her. Here are some requirements that I gathered from the interviews:

  • The camera must be lightweight
  • No wires and a minimal instrumentation
  • A discrete device that should not be noted by the follower
  • Visualize the video feed with minimal effort ...
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