AP Photo/Andrew Harnik A photograph showing Facebook CEO Mark Zuckerberg's private notes show how thoroughly he was briefed ahead of his grilling by Congress in Washington, DC, on Tuesday. One section that stood out was a clear instruction: "Don't say we already do what GDPR requires." This refers to a new European privacy law that will force Facebook to give users much more control over what data they share. The notes suggest Facebook isn't fully ready for GDPR, which comes into effect on May 25. Mark Zuckerberg had an awful lot to remember during his grilling by Congress on Tuesday, judging by pages of private briefing notes captured by a quick-witted AP photographer. The pages give us an insight into how Zuckerberg was thoroughly coached not only on predictable topics like Russian election interference, but wider areas such as the lack of diversity in Silicon Valley.See the rest of the story at Business InsiderNOW WATCH: How a woman from the 1800s became the first computer programmerSee Also:Facebook in Europe is about to get massively disrupted by new laws meant to bring it to heelMark Zuckerberg says AI won't be able to reliably detect hate speech for 'five to 10' yearsMark Zuckerberg just hinted that Facebook could offer a paid version one daySEE ALSO: Facebook in Europe is about to get massively disrupted by new laws meant to bring it to heel