To prove, Check Point has posted a video demonstrating how to hack SmartThinQ can allow an attacker to spy.
The good news is that this vulnerability has been fixed even if you use the old application, it is not easy to exploit this vulnerability.
The steps to exploit the vulnerability are not easy to implement if the hacker is not skilled.
LG updated SmartThinQ (v1.9.20 on September 29) and updated the firmware for affected smart home devices.
Check Point calls this vulnerability HomeHack and gives a detailed report here.
https://blog.checkpoint.com/2017/10/26/homehack-how-hackers-could-have-taken-control-of-lgs-iot-home-appliances/