Mahesh Kumar/Associated Press

Civil rights activists, free speech advocates, lawyers and politicians have spoken out in recent days against India’s controversial Internet laws, after two women were arrested in Mumbai for criticizing in a Facebook post the city’s shutdown after the Hindu leader Bal K. Thackeray’s death last week.

A particular target for criticism is Section 66A of the Information Technology Act, an amendment added in 2008, which, among other things, makes it a crime to digitally send “any information that is grossly offensive or has menacing character.”

Even a senior government official acknowledged recently that there may be flaws in the way the law is being used.

“At the moment, there is nothing unconstitutional about the section,” Kapil Sibal, India’s minister for communications and information technology, said in a televised interview on Monday. But, he added, there might be a need to review the law and possibly even to amend it, “if I find that this kind of abuse is taking place by misusing the section.”

The current controversy began when Shaheen Dhada, 21, wrote a post on Facebook wondering why the megacity of Mumbai had ground to a halt because of the death of a politician. “With all respect, every day, thousands of people die, but still the world moves on,” she wrote on Sunday. The post was “liked” by Renu Srinivasan, 20. Both women were arrested and charged under section 505(2) of India’s Penal Code, which relates to statements that are likely to create enmity, hatred or ill will between classes, and Section 66A of the I.T. Act. They were later released on bail.

Critics took to Twitter, lambasting the authorities for curbing the freedom of speech and expression and demanding a change in India’s I.T. law. “The law is so broad, it gives unbridled power to the authorities to register a case,” said Pavan Duggal, a lawyer in the Supreme Court who specializes in technology and Internet laws, and who called Section 66A draconian. “It leaves everything to the subjective discretion of the law enforcement authorities,” he said.

The law is so open-ended, he said, that if a person calls another a fool or a cheat on a social media platform, the recipient could bring a complaint. It covers not just public postings but also private e-mail messages sent “for the purpose of causing annoyance or inconvenience.” Making matters worse, anyone found guilty of violating the section can be fined and imprisoned for up to three years.

The crux of the opposition to Section 66A is that it violates India’s Constitution, which guarantees the freedom of speech and expression as a fundamental right. While this right is limited by some “reasonable restrictions” that seek to, among other things, protect the sovereignty and integrity of the nation and the security of the state, and to maintain public order, the Information Technology law goes far beyond the scope of such restrictions, critics argue.

“It curbs legitimate opinion,” said Mr. Duggal. If the law were followed to the letter, he said, “there would be thousands of cases every day based on discussions and debates that take place on the Internet.”

The law’s problems may be rooted in part in its hasty conception, critics say.

The first version of India’s Information Technology Act, which was enacted in 2000, was primarily meant to regulate electronic commerce, Mr. Duggal explained. It was overhauled in 2008, after the terrorist attacks on Mumbai helped expose the country’s many vulnerabilities, including those in cyberspace – the Indian authorities struggled to monitor encrypted conversations between the attackers and their handlers in Pakistan.

The changed law was passed hurriedly in Parliament’s winter session in 2008 without debate or discussion by India’s lawmakers, a lapse that is now strengthening calls for an amendment.

“The government needs to seriously relook at some of the provisions,” said Pranesh Prakash, the policy director at the Center for Internet and Society in Bangalore. Section 66A, he said, seemed to be inspired by Britain’s Malicious Communications Act of 1988 and the Communications Act of 2003.

But “even if something is legal in the U.K., it can be unconstitutional in India,” Mr. Prakash argued, because constitutional protection for speech in India is better than in Britain, which does not have a single, codified constitution.

No court in India has so far decided on the constitutionality of the law, but a lawsuit challenging it was recently filed before the Madurai bench of the Madras High Court after Ravi Srinivasan, a businessman from Puducherry, was arrested for alleging on Twitter that the son of India’s Finance Minister P. Chidambaram had “massed more wealth” than Robert Vadra, the son-in-law of the Congress leader Sonia Gandhi. (Mr. Vadra has been accused of profiting from illegal land deals.)

“The problem is that this law can be very easily misused by influential persons to curb inconvenient conversations,” said Marx Anthonisamy , a human rights activist who filed the public interest lawsuit.

He also condemned what he called the government’s double standards on online speech, arguing that the laws for online content were harsher than for printed content. While newspapers and other print media had written about the controversy surrounding the minister’s son, he said, a comment on social media was singled out for attack.

The Indian government, which has in recent months been accused of over-regulating the Internet and interfering with freedom of speech online, has repeatedly defended India’s legal framework. But critics are hopeful that the most recent controversy will catalyze change.

Stopping short of guaranteeing an amendment of the law, Mr. Sibal acknowledged that the government needs to educate law enforcement authorities that arresting the two women over a Facebook post was “not the way to use this particular section.” He also suggested that an explanation of the law should be added to narrow its scope.