If you use Alexa, Echo, or any other Amazon device, you have only 10 days to opt out of an experiment that leaves your personal privacy and security hanging in the balance. On June 8, the merchant, Web host, and entertainment behemoth will automatically enroll the devices in Amazon Sidewalk . The new wireless mesh service will share a small slice of your Internet bandwidth with nearby neighbors who don’t have connectivity and help you to their bandwidth when you don’t have a connection. By default, Amazon devices including Alexa, Echo, Ring, security cams, outdoor lights, motion sensors, and Tile trackers will enroll in the system. And since only a tiny fraction of people take the time to change default settings, that means millions of people will be co-opted into the program whether they know anything about it or not. Amazon has published a white paper detailing the technical underpinnings and service terms that it says will protect the privacy and security of this bold undertaking.