A Google executive who helped organize the January 25 protest that sparked the popular uprising in Egypt was freed from government detention Monday. The release of Wael Ghonim, who had been missing for 12 days — and an emotional television interview he gave Monday night — brought "tens of thousands" of protesters back to Tahrir Square on Tuesday "with renewed purpose." Here, a brief guide to Ghonim's role in the Egyptian revolt:

Who is Wael Ghonim?
A 30-year-old Google marketing manager, Ghonim had been the anonymous administrator of a Facebook page, "We Are All Khaled Said," in honor "of a 28-year-old Egyptian man beaten to death by police." Through that page, Ghonim was a "key organizer" of the online campaign that led to the public protests against Egyptian President Hosni Mubarak. Ghonim went missing January 28, and became a rallying symbol for demonstrators. He announced his release from government detention Monday by tweeting a short message in English: "Freedom is a blessing that deserves fighting for it." (Watch an Al Jazeera report about Ghonim's release)

What did he do after his release?
Hours after he was freed, Ghonim went to the studios of Egypt's Dream TV, where he gave an interview that was "one of the most dramatic hours of television in Egyptian history," says Dan Murphy in The Christian Science Monitor. Ghonim insisted that the protesters "are not traitors" and said the anti-Mubarak movement was "the revolution of the youth of the Internet." He broke down in tears after being shown images of demonstrators who had been killed. Ghonim also insisted that he is not a hero. "The heroes are the ones who protested, who are the ones who sacrificed their lives, who were beaten," he said. "I was just there writing on the keyboard."

How are Egyptians reacting?
Tahrir Square was packed Tuesday with "one of the biggest crowds" since the uprising began two weeks ago, and "many said they were inspired" by Ghonim, according to the Associated Press. Some on the scene chanted "Wael Ghonim is coming today," and he did join the demonstrators in the square. Also, about 150,000 people have joined a Facebook group nominating Ghonim as a spokesman for the protesters.

Sources: Associated Press, CBS News, Christian Science Monitor, New York Times, Wall Street Journal