Ewww... no!!
Powerlines are a nasty, cheap, quick hack of a solution ! Not to be recommended under any circumstances !
Power cables were never intended to transfer data ! Not only do you have all sorts of reliability and other issues, but you also have security issues to do with data snooping (and no, I don't believe any encryption claims would withstand any sort of scrutiny, even more so given most people can't even manage to setup a secure WiFi network ! ).
moosp... do yourself a favour, ignore Tone and use proper CAT5/CAT6 which were designed for the purpose of transmitting data reliably !
Sorry Tone. Powerlines are a joke, not a serious solution.