The bill died in part because of the ongoing political stalemate and general mistrust among Republicans and Democrats in Washington.

It also failed because libertarian computer users and businesses convinced lawmakers the measure would give the government enforcement and regulatory tools that could cost billions of dollars without actually improving cyber safety.

“An ineffective program would tie businesses in red tape but would do little to deter bad actors,” the U.S. Chamber of Commerce said in a letter to Congress in November. “Businesses do not have unlimited capital and human talent to devote to regulatory regimes that are ... out of date as soon as they are written.”

At the same time the Electronic Frontier Foundation, which lobbies for Internet privacy rights, said the bill was “overly vague” and may have threatened individual Web users.

“We don’t need to water down existing privacy law to address the challenges of cybersecurity,” said EFF attorney Lee Tien in a statement after the vote.

Supporters inserted some privacy protections into the measure this summer, but not enough to save it. Finding a balance among cost-effective, reliable security measures, corporate needs, and privacy rights is difficult, Blunt said.

“How to draw those lines becomes very important,” he said recently.

Cybersecurity compromise is also difficult because of the free-wheeling nature of the Internet, where full agreement on standardizing technical issues is often hard to achieve — and subject to the relentless pace of industry improvements.

The threats vary with targets, experts said, further complicating the search for a universal solution. Some computer-based activities — emails or cat pictures, for example — may be easier to protect than complicated electric grid networks or millions of bank accounts.

For those reasons, and others, grassroots support for cybersecurity legislation next year appears unlikely.

Many Americans, remembering the Y2K threat in 1999, have become jaded to perceived dangers of the interconnected Internet world, complicating the political calculations in Washington.

“Sadly, for everyone to unilaterally agree,” Silva said, “it’s going to take something catastrophic.”