By SOMINI SENGUPTA


MUMBAI, India - The three-day siege of Mumbai was a watershed for India’s prosperous classes. It prompted many of those who live in their own private Indias, largely insulated from the country’s dysfunction, to demand a vital public service: safety.

An extraordinary public interest lawsuit was filed in this city’s highest court on December 3. It charged that the government had lagged in its constitutional duty to protect its citizens’ right to life, and it pressed the state to modernize and upgrade its security forces.

The lawsuit was striking mainly for the people behind it: investment bankers, corporate lawyers and representatives of some of India’s largest companies, which have their headquarters here in the country’s financial capital, also known as Bombay. The Bombay Chamber of Commerce and Industry, the city’s largest business association, joined as a petitioner. It was the first time it had lent its name to litigation in the public interest.

Since the attacks on November 26, which killed 163 people, plus nine gunmen, there has been an outpouring of anger from unlikely quarters. On December 3, tens of thousands of urban, English-speaking citizens stormed the Gateway of India, a famed waterfront monument, venting anger at their elected leaders. There were similar protests in the capital, New Delhi, and the southern technology hubs, Bangalore and Hyderabad. All were organized spontaneously through text messages and Facebook pages.

Social networking sites were ablaze with memorials and citizens’ action groups, including one that advocated refraining from voting altogether as an act of civil disobedience. Never mind that in India, voter turnout among the rich is far lower than among the poor.

And there were countless condemnations of how democracy had failed in this, the world’s largest democracy. Those condemnations led Vir Sanghvi, a columnist writing in the financial newspaper Mint, to remind his readers of 1975, when Prime Minister Indira Gandhi imposed emergency rule. Mr.Sanghvi wrote, “I am beginning to hear the same kind of middle-class murmurs and whines about the ineffectual nature of democracy and the need for authoritarian government.”

Perhaps the most striking development was the lawsuit, a rare example of corporate India’s confronting the government outright rather than making back-room deals.“It says in a nutshell,‘Enough is enough,’”said Cyrus Guzder, who owns a logistics company.“More precisely, it tells us that citizens of all levels in the country believe their government has let them down.”

In India’s city of gold, the distinction between public and private can be bewildering. For members of the working class, who often cannot afford housing, public sidewalks become living rooms. In the morning, commuters from gated communities in the suburbs pass children brushing their teeth at the edge of the street. Women are forced to relieve themselves on the railway tracks.

No previous terrorist attack had so struck the top of Bombay society. Bombs have been planted on commuter trains in the past, but few people who regularly dine at the Taj Mahal Palace & Tower hotel, one of the worst-hit sites, travel by train.“It has touched a raw nerve,”said Amit Chandra, who runs an investment firm.“People have lost friends. Everyone would visit these places.”

Public anger could not have come at a worse time for incumbent politicians. National elections are due next spring, and security is likely to be one of the top issues in the vote, particularly among the urban middle class. It remains to be seen whether outrage will prompt them to turn out to vote in higher numbers or whether politicians will be compelled to pay greater attention to them than in the past.

“There’s a revulsion against the political class I have never seen before,” said Gerson D’Cunha, a former advertising executive whose civic group, A.G.N.I., presses for better governing.“The middle class that is laid back, lethargic, indolent, they’ve been galvanized.”

The three-day standoff with terrorists was neither the deadliest that India has seen, nor the most protracted; there have been other extended convulsions of violence, including mass killings of Sikhs in Delhi in 1984 and of Muslims in Gujarat in 2002.

Yet the recent attacks, which Indian police say were the work of a Pakistan-based terrorist group called Lashkar-e-Taiba, were profoundly different. Two of the four main targets were luxury hotels frequented by the city’s wealthy elite: the Taj, facing the Gateway of India, and the twin Oberoi and Trident hotels. They were the elite’s gathering spots and business dinner destinations.

In The Indian Express newspaper on December 5, a columnist named Vinay Sitapati wrote a pointed open letter to “South Bombay,”shorthand for the city’s most wealthy enclave. The column first berated the rich for lecturing at Davos and failing in Hindi exams.“You refer to your part of the city simply as‘town,’” he wrote, and then he begged: “Vote in person. But vote in spirit, too: use your clout to demand better politicians, not pliant ones.”

“In your hour of need today,” he added, “it is India that needs your help.”