Looking at the file, it strikes me that it doesn't seem to be quite what you think it is, namely a "relationship score" between Google+ users. People that I've never communicated with on Google+ but mailed previously have a score (and the people I've mailed most frequently have the highest scores), while people I've only communicated with on Google+ but never mailed don't have one (the fields are empty). Organizations that I've mailed also have scores, and they obviously don't have Google+ accounts.

It looks more like a "relationship score" for GMail that doesn't take into account Google+.

I wholeheartedly agree with you on this. Maybe it's due to the fact that I'm not a native English speaker, but I never meant to insinuate otherwise (after all, Google+ is very very young and the score should come from somewhere). I just wanted to share the fact that Google+ makes this score available.

Sorry for misinterpreting you. For the record, I'm not a native speaker either, which might be a source of confusion.

You need something like firebug or webkit's developer tools to get the content. If you're using Webkit: Click on the Network Tab, reload the page and wait. When it's done loading, click on XHR at the bottom. There you will see the path, and the contents.

I removed some of the parameters of the request, for safety reasons ... but if you use firebug while loading plus homepage you'll find it.