(CNN) An army of 100 life-sized cutouts of Mark Zuckerbergs took over the US Capitol lawn ahead of the Facebook founder's Senate appearance Tuesday.

The stunt is the work of global activist group Avaaz , which wants Zuckerberg, Internet CEOs and government regulators to fight disinformation campaigns across Facebook and other social platforms.

"We know Facebook is doing things to address the fake news problem, but they are doing it in a way that is too small and too secretive," Avaaz campaign director Nell Greenberg told CNN.

Advocacy group Avaaz is calling attention to what the groups says are hundreds of millions of fake accounts still spreading disinformation on Facebook.

The letter addresses four key elements the organization wants Facebook and other internet sites to address: tell the truth, ban the bots, alert the public and fund the fact-checkers.

Read More