Open or unsecured WIFI connections are a problem. They offer others cover to do whatever they want. In this case, it resulted in a Swat team that came busting in to the house by crashing the door and throwing stun grenades.
Another problem with unsecured networks is that they can be the vehicle for fraud as well as hosts for computer viruses as well as other malicious actions. A simple password protected WiFi is apt to result in perpetrators going to another WiFi which most likely will be unsecure rather than spending time and energy trying to break a password. Online threat — but SWAT team raids wrong house