Infographic: Developments in the Facebook data scandal

Facebook CEO Mark Zuckerberg’s two-day testimony in front of US congressional leaders drew the world’s attention on Tuesday and Wednesday.

During the nearly 10 hours of questioning, Zuckerberg apologized again and admitted that Facebook data was improperly used by the UK political consultancy Cambridge Analytica.

The scandal has escalated since April 4, after Facebook said the personal information of up to 87 million users may have been misused, up from a previous news media estimate of more than 50 million.

On Tuesday, the company launched a "data abuse” bounty program with a reward of up to 40,000 US dollars for people who report the misuse of data by app developers.

Here is a timeline of how the data scandal unraveled to this day:

(CGTN)