At the time Mark Zuckerberg didn't want to testify in the UK, he testified to the UK House of Commons commission to inform them about Fake News [1]
In the corporate world the strategy is to 'Engage employees', make them aware of the harms of technology and philosophy of Humane Tech. I found it enlightening to see him address the opening keynote at Dreamforce 2018 "How to Stop Technology from Destabilizing the World" [2] to a hall full of SalesForce customers.
The CHT now focuses primarily on fake news, disinformation, political influencing problems that arise from tech - i.e. the topics where the risk for civic breakdown is highest, but they have also played a role in bringing the concept of 'Time Well Spent' - focussed on healthy tech use - across at e.g. Google and Apple (but much to be done still in this area).
PS. I represent the Humane Tech Community, which is affiliated yet operates independently of the CHT, as a grassroots movement [3].
[1] https://community.humanetech.com/t/witness-account-of-trista...
[2] https://community.humanetech.com/t/must-see-video-explaining...
[3] https://community.humanetech.com/t/who-we-are-what-we-do-and...