There’s a huge amount variety between the alternative sbc providers, but I’m general:
- some are simply designed not to have various bits of hardware like the camera 22 pin connector.
- some fail to conform to the pis pin out or footprint, so hats won’t be compatible
- more commonly, documentation and support is so poor that extensive dev/Linux experience is required to get existing hardware to work
All of this makes it difficult to utilize alternatives without conducting considerable research into many different ones.
They likely buy leaked data that would include things like your full name and email, perhaps an address. Even if an address isn’t there, legal data brokers often have your address for a small payment anyways. From there they likely use something like Google Street view.