interesting. I don't know how it would be dangerous because I don't build apps or anything. Just s general question. I would like to be able to walk through my door tap my phone on s little device and not even think of WiFi on lights on bluetooth off etc etc
There is just a whole line of extra security measures that would need to be implemented. Say for example, you have it setup to connect to wifi via a tag, walk into Starbucks and set your phone on the counter that has a tag disguised near it (somehow) and it connects to an ad hoc wifi or some other wifi that is actually a man in the middle attack. Just for example basing off what you said.
Now there is a lot that can be done to prevent that, like a prompt or something but in then you're back to manually doing stuff.
Plus it should be connecting to the proper wifi without any user interaction. Which is the most secure AND easiest solution.