HI, I’m Catherine Pearce (@secvalve), the primary researcher for the Blackhat research referred to here.
Just thought I’d clarify a few things and attempt to bring some nuance back to this discussion. One of my key points in this work was to raise awareness to this tech so people can respond appropriately, in whatever way that means for them and their technology.
Firstly, Many of the techniques done in MPTCP aren't entirely novel, you could do them at the application layer if you wanted to - but MPTCP brings them to most existing tech without having to handle the complexity in the application. I recommend people see this paper if they're technically inclined: http://inl.info.ucl.ac.be/system/files/nsdi12-final125.pdf As for the discussions on congestion, flow control, and network load, there has been some research done into this, see "theoretical background" here: http://nrg.cs.ucl.ac.uk/mptcp/
One short way to think about packet switching is that packets of data should be sent wherever the best route is at the time. With TCP however, you're stuck with whatever link and address(es) you initially use. MPTCP extends TCP and frees you from this restriction.
Shifting power: Yes, one of the key things a tech like MPTCP does is shift some degree of trust away from network operators and on to the endpoints. While you should be using things like encryption, in cases where this isn't possible or efficient you are generally at the mercy of whichever networks you pass your traffic over. MPTCP gives you a bit more choice, and a bit more ability to split things up and compare difference. This is seen as bad in organizations (who like to be effectively totalitarian in their own domain), but is a good thing if you're trying to protect yourself from a network (state-level attackers).
Regarding how people can deal with this, of course they can bottleneck it, or stop it going multipath in the first place, but this prevents you from getting the benefits. Network operators shouldn't shortsightedly kill something because they don't understand it - there are more sensible ways to deal with a threat than panicking and beating it to death.
Oh, and MPTCP can also split traffic over both ipv6 and ipv4 at the same time. I find that fun to think about...
More details will come out next week -- Catherine