Trouble shooting a relatives apartment I found the internet through his power line adapter was slow because it was connecting to an apartment four floors below... Who actually had a smarter internet connection but sadly at that distance the speed was reduced. I turned on the encryption pairings and that kept it in his own flat. He did have his own electricity meter but clearly all the flats were connected. I imagine in detatched houses less of a problem. In a large building there were literally 100+ WiFi networks visible so power line was a necessary solution rather than blasting through WiFi.