The last time Cairo's Tahrir Square saw rioting of this magnitude, the year was 1977 and the president was Anwar el-Sadat. Nine out of ten Egyptians lived in poverty. Half the male population was unemployed. When President Sadat cut public subsidies for flour, cooking oil, and other staples, people took to the streets in two days of violent protest. Known as the "bread riots," the public's rage forced Sadat to restore food subsidies, but when the army stepped in to quell rioters, 800 were injured, 80 were killed, and more than 1,000 were imprisoned. In his interview with Mike Wallace following the deadly riots, President Sadat insisted "I'm proud because I have the full support of the man in the street in Egypt."
Sadat was assassinated four years later, and President Hosni Mubarak came to power.
Today's revolt against Mubarak's regime is due in no small part to empty stomachs. If you're looking for background on the longstanding economic problems and deep roots of authoritarian rule in Egypt, this 1977 "60 Minutes" piece, produced by William K. McClure, is a good place to start.