In Tunisia, the revolt led to the overthrow in January of President Zine el-Abidine Ben Ali, who had held the country in an oppressive grip since seizing power in 1987.

Ms. Ben Mhenni documented police violence against protesters in several regions while the Ben Ali regime sought to impose a news media blackout. She took photographs and wrote accounts, posting them on her blog and on her Facebook and Twitter accounts. Several French media outlets that could not enter the country were able to report on the violence because of her work.

“Sidi Bouzid is burning, self-immolations are rising in the country, and the people who are doing it have often lost any hope to get a decent life,” she wrote on her blog on Dec. 19, 2010, almost a month before Mr. Ben Ali’s fall. “Because the government is indifferent to the troubles of its citizens, we as a civil society need to take action.”

Ms. Ben Mhenni was one of many young people in Arab countries who used social media and blogs to document the protests and the subsequent crackdowns that state-controlled media ignored, providing outside news organizations that were barred from the country with rare glimpses of the turmoil in the streets and insights into the mood of the people.

“We, the bloggers, are free, and we have always refused to take part in any organization,” she wrote in a slim book about her experiences, “Tunisian Girl: Blogger for an Arab Spring” (2011). “No one is the leader in the cyber-dissidence space. There is no rule, no limit. We are far more efficient this way.”