Twitter and Facebook CEOs are making the case to US lawmakers that their warning labels on Donald Trump's false "I won" tweets served to expand "context" around the subject of misleading social posts, while they sidestepped the fundamental question of whether the warning labels are enough to protect a global audience from the harm of the original falsity or calls to violence.

Twitter CEO Jack Dorsey and Facebook CEO Mark Zuckerberg are testifying Tuesday at a Senate Judiciary Committee hearing called to question their companies' actions around the recently concluded US 2020 election.