Imagine for a moment that a malicious US terrorist cell started using Donald Trump's Twitter handle to spread fear about an impending threat; real or imagined.

Would it be right for the Donald and his aides to block them from this very high profile forum? I think the answer is unequivocally, "Yes." In traditional broadcast media, screening the public from this kind of malicious fear spreading is the role that experienced programmers at CNN or Fox would play, when choosing the guests on their shows.

The upcoming legal challenge from the Knight First Amendment Institute at Columbia University in today's news is highlighting a new frontier at the intersection of our fast moving technological evolution and the pedestrian pace of the laws that have kept us all safe for hundreds of years.

In my view, there is a fundamental ethical question that we need to ask when we're building new technologies - even things as seemingly 'neutral' as a communications platform, such as Snapchat, WhatsApp, Facebook and Twitter. Some are doing a better job of this than others. You'll recall the ethical and security issues around end-to-end encryption, and spreading of fake news.

The law isn't the right way to govern these things - fair usage policies and self governance clearly are. But this meta-debate on the ethical and societal impact of technology is going to run and run.