Want swift action on a complicated, contentious piece of legislation aimed at guarding against hackers? Invoke Sept. 11.

That’s the lesson to be learned from the rhetoric around the long-awaited online security legislation introduced in the Senate on Tuesday.

“I fear that when it comes to protecting America from cyberattack it is Sept. 10, 2001, and the question is whether we will confront this existential threat before it happens,” Senator Joseph Lieberman, an independent from Connecticut and a co-sponsor of the bill, told his colleagues, according to a prepared text sent by his office.

Never mind that it’s Valentine’s Day. There was more dread than love on the Senate floor.

Senator Lieberman’s colleague, Senator Jay Rockefeller, Democrat of West Virginia, echoed the warning. “We are on the brink of what could be a calamity,” he said. “A widespread cyberattack could potentially be as devastating to this country as the terror attacks that tore apart this country 10 years ago.”

Senate bill 2105 would authorize the federal government to regulate the security of privately owned critical infrastructure, including power grids, telecommunications networks and nuclear power plants. Much of that infrastructure is controlled by Internet-connected systems and susceptible to being hacked. Under the bill, the Department of Homeland Security would establish computer security regulations for critical infrastructure companies and levy penalties on those companies that fell afoul of the law.

The bill also calls on private companies to share information about threats and breaches with each other and the government, a provision that Senator Dianne Feinstein of California had pressed for.

She too invoked you know what. “Alongside terrorism, cybersecurity is perhaps the No. 1 threat facing our nation today, but many obstacles exist that prevent the cooperation and coordination needed to deter this growing threat,” she said in a statement.

A hearing on the bill is scheduled for Thursday.