Yea-a bunch of excitement about nothing. And the data limit they can even use is like 500MB.You are stretching this. Your neighbors aren't talking to your WiFi network directly, i.e. if you check your router's list of connected devices, it will only be your own. This is presuming your router has security set up, of course, so your WiFi network is just as secure and locked down as it was with or without Amazon devices.
Yes, your neighbor's Amazon device might be able to talk to your Amazon device and technically their data can traverse your network (and vis-versa). This also depends on if the devices are close enough for this to work anyway.
It's also important to understand that other people's Sidewalk devices won't actually be able to access, join or even see your home's Wi-Fi network, and you won't have any access to information about those devices or their users, either. Outside devices like those will connect anonymously with your Echo or Ring device over Bluetooth LE or LoRa, and your Echo or Ring device will pass their signal on to the cloud using a very tiny amount of your home network's bandwidth.
Specifically, those transmissions are capped at 80Kbps each, with a maximum data usage of 500MB each month. That might sound like a lot, but according to Statista, internet usage spiked to a peak of about 400GB per month in 2020. That's 400,000MB. 500MB is about 0.125% of that figure.
https://www.cnet.com/home/smart-hom...out-sharing-home-bandwidth-community-finding/