There are many types of cell phone jammer on the market, so if you want to block cell phone signals over a wide range, you will spend a lot of money on one of these devices. However, if you have a limited budget and are unable to purchase expensive jamming equipment, you can buy one of these portable devices, especially if your main goal is to block people in the surrounding area. In this case, I think the actual range of about 5 meters is enough, especially when you use it on a bus and want people to be quiet for a few minutes, such a mobile phone signal interference device will definitely come in handy.
It is worth mentioning outdated technologies like Blusnarfing. The term itself means using Bluetooth to invade various mobile devices. Previously, it was rarely used because of its shortcomings: hackers had to keep it within 10 meters (30 feet) of the target because it was a Bluetooth receiving range. But now, as the working range of Bluetooth has expanded, it is becoming more and more popular. Sometimes hackers can even use very sensitive unidirectional antennas to complete these hacks from a distance. However, protecting yourself from damage is very simple. The desktop WiFi signal blocker can effectively intercept the surrounding WiFi networks and protect security.
But sometimes there are dangerous mobile applications that can not only steal your money but also collect your personal information. Usually, these applications need access to your browsing history, contact list, and device physical memory. In addition, it will attempt to obtain authorization for unlimited Internet access. If you find that applications that have nothing to do with Internet services require unlimited Internet access, try to avoid this, which is the main reason for cell phone signal jamming devices in many office or business center meeting rooms.