NSA / Reuters The National Security Agency headquarters in Fort Meade, Md.

As the U.S. National Security Agency scandal has unfolded over the last few weeks, Internet giants Google, Facebook, and Yahoo have been falling over each other to publicly distance themselves from the NSA’s data collection programs, in some cases even going to a secret U.S. court to increase their transparency with the public. By contrast, the nation’s largest phone companies, including Verizon, AT&T, and Sprint, have remained stone-cold silent in the face of reports that they’ve participated in a vast, ongoing NSA data collection program targeting the phone records of tens of millions of Americans.

It’s a striking dichotomy, because the program involving the Internet companies, a data analysis system known as Prism, doesn’t even target U.S. citizens or others on U.S. soil (although it’s clear that some data associated with so-called U.S. persons has been scrutinized, thanks to linguistic wiggle-room in the parameters of the Prism program). By contrast, Verizon, AT&T, and Sprint, the nation’s three largest phone companies, have for years been participating in a separate secret program, authorized by the Patriot Act, that collects the phone records of tens of millions of U.S. citizens, including the number called, when the call was made, and the length of the conversation. This so-called “metadata” can be very revealing, and it’s reportedly being collected on most of us right now.

Reached by TIME, each of the three telecom giants — Verizon, AT&T and Sprint — once again declined to comment on their participation in NSA surveillance programs.

What accounts for the different responses by the Internet companies and the phone companies, in the face of the NSA disclosures? Part of the explanation, according to tech policy experts and privacy advocates, is that over time, many of us have grown inured to the idea that phone records can be tracked by the government. On the other hand, people seem to have a more visceral reaction to the notion that emails, instant messages, and Web-video chats are being collected and analysed. In short, government collection of Internet activity seems more intrusive than monitoring phone records. This helps to explain why the Internet firms have taken the brunt of public outrage over the NSA disclosures, as compared to the big phone companies.

(MORE: Google Challenges NSA Secrecy in FISA Court)

“I suspect that many people — perhaps sometimes without even realizing it — just don’t think of ordinary phone calls in terms of the same importance that they used to, given how much of their lives and routine communications have migrated to the Internet,” said Lauren Weinstein, a veteran tech policy and privacy analyst. Indeed, as broadband Internet access has become widely ubiquitous, many people are increasingly communicating via email, instant messaging, and Internet Protocol (IP) based platforms like Skype.

Following the disclosure of the Prism program, Google and other large Internet companies, including Apple, Facebook, Yahoo, and Microsoft vigorously objected to the notion that they allow the government unfettered or “direct” access to their servers. Google has even petitioned the secret Foreign Intelligence Surveillance Court to relax restrictions on the information it can reveal about national security requests, claiming such restrictions violate the company’s right to free speech under the First Amendment. In its motion, Google said that its “reputation and business has been harmed by the false or misleading reports in the media.”

In contrast to the Internet giants, the nation’s largest phone companies have observed a disciplined silence in response to the NSA disclosures. None of them have pushed back with anything approaching the vigor — and occasional indignation — of the Internet companies. There have been no statements, no blog posts, and no public question-and-answer sessions with top executives. Furthermore, none of the phone companies have gone to the FISA court requesting permission to be more transparent about top-secret national security requests. (Or if they have, such requests have not been made public.)

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A Verizon spokesperson confirmed that the company has not issued any statements in response to the NSA disclosures. The spokesperson did, however, point to an internal memo to employees from Randy Milch, Verizon’s executive vice president and general counsel, in which he addressed certain aspects of The Guardian’s report about the top-secret FISA court order that requires Verizon to provide the NSA on an “ongoing, daily basis” with metadata information on all phone calls made by its U.S. customers.

In the memo to Verizon employees, excerpts of which were provided to TIME, Milch said the company has “no comment on the accuracy of The Guardian newspaper story or the documents referenced, but a few items in these stories are important.” Milch noted that the alleged court order “compels Verizon to respond; forbids Verizon from revealing the order’s existence; and excludes from production the ‘content of any communication…or the name, address, or financial information of a subscriber or customer.'” Milch added: “The law authorizes the federal courts to order a company to provide information in certain circumstances, and if Verizon were to receive such an order, we would be required to comply.”

Last month, The Wall Street Journal reported that the NSA cell phone metadata program extends to AT&T and Sprint, as well as Verizon. The purpose of the program, according to the paper, is to identify possible terrorist threats to the United States. The Journal said the government’s cell phone data collection effort “evolved out of warrantless wiretapping programs begun after 2001, [and] is now approved by all three branches of the U.S. government.” A spokesperson for Sprint confirmed that the company has not issued any statements in response to the NSA disclosures, and declined to comment further. A spokesperson for AT&T also declined to comment.

“The silence of the telecom giants speaks volumes, and suggests that they may be more deeply involved in the NSA’s surveillance program than we now know,” said Tim Karr, a policy expert at Free Press, a Washington, D.C.-based tech policy and civil liberties advocacy group. He noted that unlike most Internet companies, AT&T is one of the most powerful companies in Washington, so it may not feel the need to push back as publicly, given its wide-ranging influence in the nation’s capitol. “AT&T’s clout is the result of decades upon decades of intense lobbying and relationship building,” said Karr. “In contrast, the Internet companies are new to this game and it shows.”

(MORE: Google: We’re No NSA Stooge and We’ll Prove It if the Feds Let Us)

One of the broader mysteries about the NSA revelations is the extent to which the American public is really upset about the government’s secret national security data collection and analysis. Civil libertarians and privacy experts have been up in arms about the disclosures, but a recent TIME poll found that Americans remain sharply divided about the government’s use of the surveillance programs. Forty-eight percent of Americans approve of the surveillance programs, the poll found, while 44% disapprove, a statistical tie given the poll’s four-point margin of error. And a majority the poll’s respondents said that the surveillance programs have helped protect national security.

This ambivalence about the government’s secret surveillance programs reflects the broader tension — highlighted repeatedly by lawmakers in recent weeks — between national security and individual privacy. One thing is clear: The vast scope of the surveillance programs could not be possible without the participation of the nation’s largest technology and telecommunications companies.

The striking contrast in the responses to the NSA snooping controversy by the Internet titans and the phone giants underscores the evolving nature of the public’s relationship to technology, and the emergence of new Web-based forms of communication. The phone giants may simply have calculated that the public is more willing to accept phone tracking, than the collection of emails, instant messages, and other Internet activity, so it’s best for them to keep their heads down and ride out the storm. Clearly, the Internet companies do not feel the same luxury.