大多数周界防护如篱笆、围墙等,都不能有效地阻止罪犯、盗贼、破坏分子或恐怖分子入内,于是转而采用电子防范和探测系统。但是这些系统大多数是单纯的探测和报警。由于外部环境不同和变化,它们常常发生误报或漏报,为弥补这种缺陷,采用报警确认系统,如CCTV或声频复核,以增加可靠性,但是安装这些系统成本高。这些电子防范措施没有一种是主动保护周界安全,并把入侵者拒之于外,因为它们都是“被动”的,而不是“主动”的。那么为什么我们不使篱笆带电并同时把它接到报警系统呢?有人会认为这是不合法的。我们说,否,它不是非法的。实际上对于电网 Most perimeter protections, such as fences and fences, can not effectively deter criminals, thieves, saboteurs or terrorists from entering the building. Instead, they have adopted electronic surveillance and detection systems. However, most of these systems are simple detection and alarm. Due to the different external environment and changes, they often have false positives or false negatives. To compensate for such defects, alarm verification systems such as CCTV or audio recheck are added to increase reliability, but the cost of installing these systems is high. None of these electronic preventive measures proactively protect perimeter security and keep intruders excluded because they are all “passive” rather than “active.” So why do not we power the fence and at the same time connect it to the alarm system? Some would think that this is not legal. We say no, it is not illegal. Actually for the grid