With the plummeting prices of wireless LANs, businesses, schools and home users have all rushed out and installed low-cost WLANs. Many homes and businesses have inadvertently opened their network to outsiders because radio waves can travel through walls, out onto the street and even into your neighbor’s house. Without encryption, there’s nothing to prevent a hostile computer user from hooking up with your access point and scoping out your internal network. “War driving” has become a popular hacker pastime.”]
Source: https://www.csoonline.com/article/2116113/wireless-network-security.html