Google, Microsoft, Yahoo, and Facebook all say that they require full warrants in order to provide the contents of emails and messages to government entities, The Hill reports. That's a higher standard than currently required by US law, which as of now is largely defined by the Electronic Communications Privacy Act (ECPA). The ECPA was passed in 1986 and sets a relatively low bar for accessing private data — but Senator Patrick Leahy has been trying to pass a revision that would require warrants, though the bill stalled out in the last Congress.

While the update for the ECPA is pending, those four companies all gave The Hill variations on the same statement, that they have policies that require a warrant before providing the content of messages. Those policies aren't backed by the force of law yet, however, and there are other reasons for users to still be concerned about how much data government entities can get from these companies without a warrant.

"If they come for registration information, that's one thing, but if they ask for content of e-mail, that's another thing."

To get a clearer picture, you can look at Google's most recent transparency report, which revealed that 68 percent of the data requests the company receives from government entities come in the form of subpoenas that may not require a full warrant. Although Google's policy is to require a warrant for the content of an email, it still may produce some sort of data in response to ECPA requests — in fact, 88 percent of the time, it did just that. Speaking to Ars Technica, Google spokesperson Chris Gaither said, "If they come for registration information, that's one thing, but if they ask for content of e-mail, that's another thing." Additionally, Google isn't allowed to provide a full picture of the data it provides when the requests come through FISA courts or the USA Patriot Act in its transparency report.

Although the companies' policies may not be backed by the full force of current law, each told The Hill that they believe the fourth amendement backs them up. Senator Leahy has promised to make updating the ECPA a top priority in his role as the chairman of the Senate Judiciary Committee.