Comment by AtlasBarfed

It took this far down in the comments to get to some inkling of the meat of this.

It relys on some singular or small set of donated servers?

NAT <-> NAT traversal is obviously the biggest motivator, since otherwise you just scp or rsync or sftp if you don't have the dual barrier.

Is the relay server configurable? Seemed to be implied it is somewhat hardcoded.