The executive will testify to politicians from Argentina, Brazil, Canada, Ireland, Latvia, Singapore and the UK on everything ranging from fake news and misinformation to how the company handles data breaches. Most recently, it's concerned about the recent New York Times exposé raising questions about Facebook's knowledge of and response to Russian election meddling campaigns.

Allan's testimony will, to some extent, be for show. After his session, representatives from each parliament are poised to sign a collection of "International Principles" for laws governing the internet -- they already have an idea as to what they want, even if it isn't legally binding. However, it won't be surprising if the hearing influences long-term internet policies in the UK and other countries in attendance.