MOSCOW — Violetta Volkova woke up that fateful December morning a hard-hitting mergers and acquisitions lawyer. Before the day was over she was springing neophyte demonstrators from jail. In a matter of weeks she would be defending some of Vladimir Putin’s worst enemies, a punk-rock group among them. A year later she was a widely known human rights lawyer.

Many Russians changed Dec. 5, 2011, when Muscovites, infuriated by what they considered fraudulent parliamentary elections the day before, protested in unexpectedly large numbers. The disgruntled young and passive middle class went out onto the streets, for the first time willing to join a protest. Leaders began to emerge from once barely known opposition movements. The punk rockers began planning political protests that would end in a performance in Moscow’s main cathedral. Soon lots of people needed lawyers.