On the sticker on the back of my bluetooth keyboard that allows me to touchtype when using my mobile phone are some words of wisdom: Operation is subject to the following two conditions: 1. This device may not cause harmful interference, and 2. This device must accept any interference received, including interference that may cause undesired operation. I laughed out loud when I read it. It’s true that in order to feel okay one must accept the harmful interference that happened in the past.