Theoretically, there is indeed a possibility of stealing information by using unauthorized electromagnetic radiation generated by electronic devices when they are working (including signals transmitted through power lines). This type of attack is sometimes called a "TEMPEST" attack or a side channel attack in the security field. Here are some details: 1. Principle Introduction Electronic devices (especially high-speed digital circuits) generate weak electromagnetic waves and current fluctuations during switching and calculation processes. These signals may propagate along power lines or other conductors. In theory, by capturing and analyzing these signals with high-precision instruments, it is possible to extract certain patterns or data features related to the information processing process. 2. Existing Research and Background Some studies in the past have shown that under certain conditions (such as close to the target device, in a poorly shielded environment, etc.), by complex processing of electromagnetic leakage signals, some of the operations or data changes originally performed inside the device can be restored. This type of research was initially aimed at the military and intelligence fields, so there are strict protection standards. Academia and industry are also constantly introducing better shielding technologies and encryption algorithms to reduce such risks. 3. Technical Challenges Although theoretically possible, in reality, this type of side channel attack faces extremely high technical difficulties, including: • The signal is weak and easily masked by noise, requiring extremely sensitive and high-resolution measuring instruments; • Analyzing the signal requires very deep knowledge of physics and signal processing, and customized analysis is required for specific devices; • Modern computer and power supply designs usually adopt strict electromagnetic compatibility (EMC) design, and high-quality power supply filtering and shielding measures can significantly reduce leakage signals. 4. Legal and ethical issues It should be pointed out that unauthorized monitoring and information collection of other people's equipment obviously involves illegal eavesdropping or privacy infringement, and may also violate data protection and national security related legal provisions. Therefore, even if it is technically possible, it must not be attempted or used for illegal purposes. In general, although it is theoretically possible to obtain information about the data processing process being processed by a computer by analyzing power lines and other means, and there are related research cases in specific experimental environments, due to the huge technical challenges and strict restrictions of laws and regulations, this method is very difficult to apply in practice, and most of them are aimed at highly sensitive military and intelligence applications.