Skyrocketing sales in online stores reflect that these phone cases, which can turn mobile phones into candid shooting tools, are a hundred times more dangerous than pinhole cameras.

In the past week, the term "refractive phone case" has appeared intensively in reports ranging from local TV stations to China Central Television.

Some time ago, "Xiao Li Helps" from Henan Radio and Television Station first exposed this product. Shortly after, "China Sound" of China National Radio and CCTV followed up one after another, turning a seemingly ordinary consumer rights protection report into a top trending search across the whole network. After sorting out information from multiple sources, Leitech (ID: leitech) found that this gray and black industrial chain is indeed very worthy of vigilance for ordinary people.

(Source: Luo Video)

How harmful is the new generation of "secret shooting phone case"?

The principle of this gadget is not complicated once you figure it out. It embeds a 45-degree miniature prism at the camera opening of the phone case, and uses light refraction to guide the images from the side or even the oblique lower direction to the phone camera.

When the phone is placed flat on the table and the screen is off, other people see that the lens is facing direction A, but it is actually shooting direction B. The black-screen recording software sold by merchants as a supporting product makes the whole process silent without any indicator light.

From the appearance of the phone and the screen status, people around can't tell at all that it is recording. Moreover, there will be a blurred black edge on the edge of the image after prism refraction, and merchants directly teach users to zoom in and crop the image, making the output effect quite "usable".

(Source: Minsheng Channel of Henan Television)

There are mainly two types of refractive phone cases on the market. The holed version sells for 300 to 500 yuan, the light inlet position is not covered by a plastic shell, and the prism component inside the shell can be seen with careful observation. The non-holed version can sell for 700 to 800 yuan, which uses light-transmitting plastic close to the color of the shell to completely cover the prism. The two versions have the same function, and the price difference is paid for the degree of concealment. According to reports from media such as Henan Television, many merchants contacted by reporters said that refractive phone cases are selling very well, and they are even out of stock.

(Source: Social Media Platform)

In fact, the cost of this kind of refractive phone case is very low. On e-commerce platforms, the retail price of optical components such as prisms is only tens of yuan. A plastic shell plus a prism worth tens of yuan, with a label that "those who know know", the premium directly increases by more than ten times. And this premium has nothing to do with conventional selling points such as drop resistance, magnetic attraction, and heat dissipation. What people buy is obviously not the industrial design.

(Source: E-commerce Platform)

To put it bluntly, what it sells is exactly the two words "secret shooting".

Merchants have different promotion words. Some product pages do not introduce the functions and uses, just put a few simple product pictures with the sentence "those who know know". Some simply disguise it as for formal purposes, and some promotional materials on product pages even show stockings-clad beauties and big beds, with their purpose completely clear.

There is another point that many people don't know. The optical solution of the refractive phone case had nothing to do with secret shooting at the very beginning. Its prototype is a casino cheating device, which uses prisms to change the shooting angle to read playing card information and cooperates with recognition software to cheat, and a set of such device can sell for more than 10,000 yuan. Later, this technical route was transferred to phone cases, and the target users changed from gamblers to secret shooters.

With lower production cost and larger target group, refractive phone case naturally becomes a profitable business. At present, there are still merchants selling the so-called "card game equipment" as a complete set online, which connects mobile phones to imaging devices and supporting software, claiming that it can see through ordinary playing cards, and the price is not cheap.

Harder to detect than pinhole cameras

There is a key difference between a refractive phone case and a traditional pinhole camera, which directly determines that the former is more difficult to detect.

The traditional pinhole camera is an independent image acquisition device with its own power supply module, image sensor and signal transmitting device. Although this kind of device is hidden, precisely because it has independent electronic components, it can be detected by means such as radio frequency detection and infrared scanning, which is the basic working principle of the vast majority of anti-secret shooting detectors and mobile apps on the market at present.

The refractive phone case is completely different: it does not add any extra camera, but only uses a piece of optical glass to change the light inlet path of the original lens of the mobile phone. It has no independent power supply, no wireless signal, no heat generation, and conventional pinhole camera detection devices can do nothing about it.

In other words, the process of turning a mobile phone into a secret shooting tool by it is at the physical level, without any electronic modification. For secret shooters, after removing the prism case, the mobile phone is just an ordinary mobile phone without any trace of modification that can be traced back. This physical solution also has an implicit convenience: there is no need to charge the device specially, no need to consider battery life, and it can work continuously as long as the mobile phone has power.

Moreover, pinhole cameras are already a well-known illegal secret shooting tool, while refractive phone cases are not really understood by the public at present, so most of the time ordinary people will not be vigilant against them.

(Source: Yangshipin)

From a legal point of view, both of these two secret shooting tools are illegal. Even if there is no hardware modification, just marking "prohibited for secret shooting" cannot exempt the seller from liability. In fact, some merchants send the shell, lens cover and prism in three separate parcels, and then guide buyers to use what glue, where to stick it, and in what direction to install it. This kind of operation itself is to avoid platform review, which is a typical case of trying to prove one's innocence only to expose one's guilt.

As for the sentence "prohibited for secret shooting", it not only cannot exempt the seller from liability, but also plays a precise marketing effect in a disguised form. The more it emphasizes the prohibition, the more it clearly tells potential buyers what this thing is used for.

The response speed of the platforms is faster than expected. At present, searching for "refractive phone case" directly on mainstream e-commerce platforms such as Taobao, Pinduoduo and Xianyu can no longer find results, indicating that the keyword has been blocked.

However, this kind of phone case is still sold in a more hidden way. We can still see related posts on some social platforms. Although the posters only posted pictures and the copy is only one or two sentences, people who browse the posts can already understand what it is. Moreover, many people in the comment area have expressed their willingness to place an order. Relatively speaking, this more obscure, code-word-based sales model is easier to break through the review mechanism of the platforms.

(Source: Social Media Platform)

The secret shooting tricks emerge in endlessly, how can ordinary people prevent it?

For ordinary people, there is a relatively simple way to identify this kind of phone case without professional equipment.

The most critical step is to check the camera opening of the phone case. A normal case only has a simple opening, through which you can directly see the lens glass of the mobile phone itself. If there are extra lenses, reflective structures or angled transparent components in the case, you need to be highly vigilant. The advanced method is to use a flashlight to illuminate the lens area obliquely: a normal case will not produce abnormal reflection, while a prism will form a clear bright spot. This method is especially effective in a dark environment. Of course, a more direct and simple method is to remove the phone case to "see the clues" when you find a suspected situation, but this requires the consent of the other party and may affect the atmosphere on site.

Vigilance at the scenario level is also very important. Fitting rooms, hotel rooms, restrooms, subway carriages and other areas are all high-incidence scenarios of secret shooting. If someone deliberately places the mobile phone flat with the screen off in these occasions and the placement angle is obviously deliberate, it is always right to keep a distance. Of course, there is no need to panic excessively. It is a very common posture to place the mobile phone flat on the desktop in daily use, just like putting the mobile phone face down on the table during a meeting, no one will find it strange. The focus is to check whether there is an extra optical structure on the case, not what posture the mobile phone is placed in.

There is also a possible misunderstanding that needs to be clarified. Before that, there has always been a kind of phone case with a built-in sliding baffle on the market, which sells for ten to tens of yuan. Its function is to use the baffle to cover the front lens of the mobile phone to prevent apps from secretly adjusting the camera in the background.

It is completely different from the refractive secret shooting case: the anti-secret shooting case is a device to protect oneself, while the refractive case is a tool to infringe on others. The two types of products are completely different in appearance and purpose, do not confuse them just because of the words "anti-secret shooting". In addition, there are also apps and devices on the market that are specially used to detect pinhole cameras, but they mainly find independent cameras by scanning Wi-Fi signals and infrared light sources, which are basically ineffective for pure physical solutions such as refractive phone cases.

(Source: E-commerce Platform)

Back to the incident itself, the optical principle of the refractive prism is indeed neutral. In fact, in the camera field, it is very common to use prisms to manipulate the optical characteristics of the lens. The common periscope lenses on current flagship mobile phones are basically equipped with prism modules, so as to achieve a larger zoom ratio while controlling the thickness of the lens. And traditional periscopes and telescopes also use prisms as devices.

However, for the refractive phone case, the originally ordinary device of refractive prism has been completely led astray by the profit-driven gray and black industry. These manufacturers and sellers know very well what they are selling, and edge-cutting marketing and disclaimer statements are only to avoid legal punishment as much as possible.

For platforms and regulatory authorities, this centralized cleanup should only be the beginning. Only by blocking the sales and distribution channels, detecting the evasion methods of lawbreakers such as keyword slang and private domain drainage, and curbing the production and manufacturing sources can the problem be truly solved. The emergence of refractive phone cases reminds everyone: the threshold of secret shooting tools is being reduced from a complex solution that requires technical modification to just buying a case, which is more dangerous than we thought.

However, for ordinary people, knowing one more secret shooting technique is already a kind of prevention in itself.