On Nov 20, 2013, at 7:35 AM, Hector Santos <hsantos@xxxxxxxx> wrote: > But I'm not sure Facebook, G+, LinkedIn and the like are good examples since they are shifting their form of "spam" to embedded online streams -- ads. This is completely orthogonal to the question we are discussing. If you can do "friending" in a federated environment, which is really not all that hard to do, then you have control over the user agent and the transport, so nobody can inject ads. It is because we haven't done this yet that we have to put up with ads on the services that _have_ done it, in a non-federated environment. (Although likely their environments look federated on the inside!)