“We can’t be sitting in a role where we decide what is good or what is bad based on our own personal biases,” he said. “That’s a huge slippery slope.”

Many U.S. agencies are customers, but so is WikiLeaks, the whistle-blowing organization. CloudFlare has consulted for many Wall Street institutions, yet also protects Anonymous, the “hacktivist” group associated with the Occupy movement.

Prince’s stance could be tested at a time when some lawmakers in the United States and Europe, armed with evidence that militant groups rely on the Web for critical operations and recruitment purposes, have pressured Internet companies to censor content or cut off customers.

Last month, conservative political lobbies, as well as seven lawmakers led by Ted Poe, a Republican from Texas, urged the FBI to shut down the Hamas Twitter account. The account remains active; Twitter declined to comment.

MATERIAL SUPPORT

Although it has never prosecuted an Internet company under the Patriot Act, the government’s use of the material support argument has steadily risen since 2006. Since Sept. 11, 2001, more than 260 cases have been charged under the provision, according to Fordham Law School’s Terrorism Trends database.

Catherine Lotrionte, the director of Georgetown University’s Institute for Law, Science and Global Security and a former Central Intelligence Agency lawyer, argued that Internet companies should be more closely regulated.

“Material support includes web services,” Lotrionte said. “Denying them services makes it more costly for the terrorists. You’re cornering them.”

But others have warned that an aggressive government approach would have a chilling effect on free speech.