After a federal court ordered Apple to help unlock an iPhone used by an attacker in a December mass shooting in San Bernardino, California, the company’s chief executive, Timothy D. Cook, penned a passionate letter warning of far-reaching implications beyond the case.

The response from other technology companies? A mix of carefully calibrated support and crickets.

Late Wednesday, Sundar Pichai, the chief executive of Google, said on Twitter that law enforcement demands to hack customer devices and data “could be a troubling precedent.” Not long afterward, Reform Government Surveillance, a coalition formed by Apple, Google, Microsoft and Facebook, released a broad statement that did not mention the Apple case or Cook’s letter but said technology companies should not be required to put “back doors” — the equivalent of a tech entryway — into their products.

It took almost another 24 hours for Facebook and Twitter to weigh in. On Thursday, Jack Dorsey, Twitter’s chief executive, posted that the company stands with Cook and Apple. Facebook issued a statement that did not mention Apple but said it would “fight aggressively against requirements for companies to weaken the security of their systems.”

Asked about Apple’s opposition to the court order, representatives of Microsoft and Amazon declined to comment.

The range of reactions highlights the complicated set of factors influencing tech companies’ responses to government demands for customer data in the era after revelations by Edward J. Snowden, the former intelligence contractor, of widespread government surveillance. Some companies may be keeping their heads low to avoid becoming targets during the raucous presidential campaign, while others may fear that being too vocal will jeopardize government sales and relationships with law enforcement, privacy experts said.

“The issue is of monumental importance, not only to the government and Apple but to the other technology giants as well,” said Tom Rubin, a former attorney for Microsoft and the U.S. Justice Department, who is now a law lecturer at Harvard University. “Those companies are undoubtedly following the case intently, praying that it creates a good precedent and breathing a sigh of relief that it’s not them in the spotlight.”

Cook vowed to fight a federal court order that the company help the FBI bypass security measures on the iPhone because he fears complying could seriously weaken privacy protections for Apple’s customers. If the government is successful, lawyers and privacy advocates warn, other tech companies could be approached to provide back doors into their products for law enforcement.

Some Silicon Valley luminaries were more direct in their support of Cook, including Jan Koum, the chief executive of WhatsApp, the mobile messaging app owned by Facebook. In a message posted to Facebook, Koum said he admired Cook’s position on privacy.

“We must not allow this dangerous precedent to be set,” Koum wrote. “Today our freedom and our liberty is at stake.”

But behind the scenes, there was discomfort among some companies that have generally allied themselves with Apple on the topic of government surveillance.

All of the companies involved in Reform Government Surveillance, including Apple, acknowledge that they often comply with law enforcement requests for customer data when under order from a court. Apple’s stance in this case seemed overly antagonistic to some companies in the coalition, according to people privy to conversations on the matter who spoke on condition of anonymity because they were not authorized to speak on the record.

In its statement on Wednesday, Reform Government Surveillance chose its words carefully. The association’s member companies, the statement said, “remain committed to providing law enforcement with the help it needs while protecting the security of their customers and their customers’ information.”

There was also disagreement about Apple’s tactics. Gunter Ollmann, chief security officer at Vectra Networks, an information security company in San Jose, California, argued that the government’s demand that Apple help unlock the San Bernardino shooter’s iPhone was in line with similar one-time requests and that Apple was creating an unnecessarily high-stakes battle by framing the unlocking as creating a universal back door.

“I’m concerned that since Apple has attempted to deny the FBI request citing use of ‘back doors,’ should they lose this legal argument, the repercussions could be extensive to the entire security industry,” he said in a blog post.

If Apple had instead framed the issue as more of a tech-specific matter, “the prospect of a lost appeal would be greatly limited,” rather than “being included in appeals over anti-terrorism and a specific instance of a horrific crime,” Ollmann added.

Privacy advocates speculated that one reason Apple was willing to stake out a bolder position against what it saw as law enforcement overreach was that it is not as eager for government business as some of its rivals. Amazon has a large deal with the CIA to help run its cloud computing operations, for example.

On Wednesday, Microsoft promoted a deal with the U.S. Department of Defense under which the department will standardize its computers on the company’s Windows 10 operating system. Microsoft has also pushed back against the government on issues including a court case in New York involving an effort to get Microsoft customer data stored outside the United States.

Marc Rotenberg, president of the Electronic Privacy Information Center, a privacy advocacy group, said some tech companies “are a little bit uneasy doing things on the law enforcement side that might disrupt their ability to win contracts.”

Privacy advocates also said that Apple was taking a stronger position on privacy matters because its business does not hinge on the online collection of large amounts of consumer data, unlike the operations of other tech companies like Google, Facebook and Twitter. In the past, Cook has contrasted the privacy policies of Apple, which makes the overwhelming majority of its money by selling devices like the iPhone and Macs, with those of Internet companies that make their money from advertising.

“A few years ago, users of Internet services began to realize that when an online service is free, you’re not the customer,” Cook wrote in a letter on privacy posted on Apple’s site in 2014. “You’re the product.”

Apple’s absolutist position is also seen by many as a reflection of Cook’s view that privacy is a human right.

“They’re deeply a consumer company,” said Ryan Calo, an assistant law professor at the University of Washington. “They’re less reliant on information as a business model. They sell things. I really think their CEO has religion on privacy and personality matters.”

© 2016 The New York Times Company