Zack Nelson posted a video where he puts a Nexus 6P through a thorough torture test. He eventually bends the phone in half. The video draws lots of criticism because during the scratch test he actually cracks the glass on the front damaging the structural integrity of the device.
Shortly after the video was uploaded I did a bend test of my own, and had determined the phone was pretty dang sturdy! Max from Zedomax did a more scientific bend test where he placed 90lbs in the center of the device and it did not bend.
Zack has posted another bend test video. According to Zack's new video the phone features a dove joint holding the bottom metal and plastic inside together. This is a weak point when it breaks it destroys the integrity of the phone. The side wall of the phone in the space between the power and volume rockers is also made up of extremely thin aluminum. With enough force it will also rip like paper. Zack is applying an insane amount of pressure on the device to make this bend happen in the fashion it does. While the video is concerning I would not be worried that your phone will bend in half. Unless you go Incredible Hulk on it like Zack!