Facebook has promised to double its global headcount from a year ago, with the new employees being devoted to Cleaning Up The Web.

The pledge comes ahead of a Congressional grilling of America's two giant internet platforms (and Twitter) today.

All three face scrutiny not just for their click-driven advertising models, but for their failure to accept responsibility for the content that flows over the network, ranging from terrorist material to propaganda.

Facebook employed just under 20,000 staff worldwide less than a year ago. But then came Trump. Earlier this year it promised to boost its minimal policing efforts with 10,000 new employees. Now that number has doubled to 20,000.

It's a significant shift for a platform business, where both the legal liability framework and the economics incentivise Facebook to do as little as possible. The entire premise is based on using algorithms to avoid human labour (and human judgement).

It's five years since the BBC's Rory Cellan-Jones set up a fake business on Facebook and gained thousands of "likes" and clicks, many of which were, er, from fake accounts too. Facebook didn't seem to care. It was all "engagement", which justified its advertising model.

So. That went well.

Also recall that when Facebook introduced its controversial "Trending Topics" in 2014, it used teams of lowly paid human "curators". Last spring it fired almost all of them, choosing to rely instead on algorithms. That decision, allied to Facebook's incentives which rewarded clicks, meant that Trending Topics became a cesspool of spurious material.

CEO Mark Zuckerberg's first instinct was that "fake news" had little impact on voters whose deeply entrenched views had taken decades to form. He may well be correct. But Facebook's behaviour only emphasised its own lack of social responsibility. What happens here has nothing to do with us!

That doesn't really cut it any more. ®