Why is the RIAA is Targeting Internet2 Users?

The RIAA press release is careful to call Internet2 a "specialized" network, but many press stories have depicted it a private network, separate from the main Internet. In fact, Internet2 is not really a separate network. It's more like a set of express lanes for the Internet, built so that network traffic between Internet2 member institutions can go faster.
(The Washington Post article gets this point seriously wrong, calling Internet2 "a faster version of the Web", and saying that "more and more college students have moved off the Web to trade music on Internet2, a separate network ...".)
...Given all of this, my guess is that the RIAA is pushing the Internet2 angle mostly for policial and public relations reasons. By painting Internet2 as a separate network, the RIAA can imply that the transfer of infringing files over Internet2 is a new kind of problem requiring new regulation. And by painting Internet2 as a centrally-managed entity, the RIAA can imply that it is more regulable than the rest of the Internet.