i would like to see what kind of perfect system you have in mind.
imo nothing is perfect.
this is the internet we are talking about, it was kind of sad the other day that some count ruled sending of count document to someone's facebook account is a valid form of transfer. how one protect a real-life "identity" online become an issue i start to worry about. i mean how can they be sure that one from facebook is the one in real life.
okay my point is, with all data available still no one can be sure someone is "this one" behind the computer. proxy is just one way of masking yourself as a different person, you can have dynamic ip etc. so i would like to hear your solution to tackle this problem that not only we have but the world is having.
let see ... someone assumed i would have the mac address of everybody which was just an assumption. I have thought of sms activation but of course not everyone has a cell phone so that will give a huge blow to the number of reviews we get.