You'd need to hunt for things like
http://www.decix.de/info/traffic.html - especially router nodes that connect states and countries would be interesting. Some big corporations, universities and cities have internal high-speed fiber nets (not just LANs), and are then routed on to "the rest of the internet" with somewhat less capable connections.
Also, more and more individual people are starting to get high-speed (10mbit) fiber at home - some of the power companies in Denmark have become tired of
TDC's monopoly on the copper lines, so they've been digging fiber-optic cables for a lot of years, and are now offering
fast internet at decent prices. Obviously there's no problem routing all this traffic internally, what happens when a mere 1000 users max out their 10mbit line?
I can't help but think about the "straws and pipes" analogy here, since a 1000 10-mbit users maxed out would be ~10gbit/s of traffic. And from what I can tell (from things like the amount of "remember to dig down your fiberoptic cable" postcards I've seen at post.dk), there's a lot of fiber users already. And I'm willing to bet that a lot of them are getting fiber for warezing purpose, after all you get 10000/10000 synchronous rather than async 8000/512 ADSL.
So, do those fiber providers have some insane interconnects, or are they overselling massively?