I don't like what these guys are posting about but should we really abandon freedom of speech over it? Wouldn't that be an example of the terrorists winning?
The problem is that not all countries consider this free speech. If you're hosting a Diaspora pod in the UK, then having this material on your system is considered terrorism.
In the UK -- simply linking-to, reporting, or even viewing of this material is considered illegal under anti-terrorism laws... (I can understand if it's distasteful, or socially frowned upon... but illegal to view a video? come-on...)
I don't think "free speech" means what you think it means. Your freedom to speech, does not give me the obligation to publish your speech on my website.
In this case the Diaspora team is using their free speech to suggest that various pod administrators choose not to publish some particularly nasty speech.