Unitymedia has this map of their "Wifispots" which is a second wifi network their newest routers will automatically open, which is free to use for all of their customers. What's interesting is that this also maps where people subscribe to their service. I'd love to see someone who knows their stuff analyze this map (it only loads if you allow it access to your location fyi) https://www.unitymedia.de/privatkunden/internet/unitymedia-wifispot/wifispotfinder/
@noiob frankly I've always wondered if there isn't a way to turn that off on my router
mostly because while I'm extremely for freely accessible internet for everyone anywhere in the world I'm not at all down for that same idea but only for rich people/corporate customers while everyone else gets to shell out tons of money on mobile data
@Thaminga you can turn it off! But the setting is not on your router, but on the customer service website
@noiob I don't think there is, unfortunately :c