Last year, I installed an older version of this and 3 months later I got a nasty email from COMCAST telling me I was using more than a TB per month and was going to get charged a fortune unless I stopped. It was really hard to pinpoint it as the cause because when I was investigating, the screensaver turned off. I think the newer version caches thankfully.
Note that it does download a whole bunch of HD videos -- don't start this on mobile broadband!
[1] https://github.com/JohnCoates/Aerial