Real-time detection, in this context, does not mean seconds. It may be unnecessary to take action if it does not spread. In practice, rapid response could mean minutes or hours. Time enough for an algorithm to detect a wave of news that seems suspicious and is gathering momentum, potentially from multiple sources. Also, enough of a window to gather evidence and have it considered by humans who may choose to arrest the wave before it turns into a tsunami.
I know a thing or two about algorithms processing news. I built Google News and ran it for many years. It is my belief that detection is tractable.
I also know that it is probably not a good idea to run anything other than short-term countermeasures solely based on what the algorithm says. It is important to get humans in the loop — both for corporate accountability and to serve as a sanity check. In particular, a human arbiter would be able to do proactive fact checking. In the above example, the Facebook or Twitter representative could have called the press office of the Holy See and established that the story is false. If there is no obvious person to call they could check with top news sources and fact checking sites to get their read on the situation.
Krishna Bharat
Still on the subject of fake news and online manipulation: fast detection and prevention doesn’t look complicated if you think about it – and the article comes from the founder of Google News, an ex-Google employee.