Twitter declined to make it easier for the government. But other companies were more compliant, according to people briefed on the negotiations. They opened discussions with national security officials about developing technical methods to more efficiently and securely share the personal data of foreign users in response to lawful government requests. And in some cases, they changed their computer systems to do so…

The companies that negotiated with the government include Google, which owns YouTube; Microsoft, which owns Hotmail and Skype; Yahoo; Facebook; AOL; Apple; and Paltalk, according to one of the people briefed on the discussions. The companies were legally required to share the data under the Foreign Intelligence Surveillance Act. People briefed on the discussions spoke on the condition of anonymity because they are prohibited by law from discussing the content of FISA requests or even acknowledging their existence.

In at least two cases, at Google and Facebook, one of the plans discussed was to build separate, secure portals, like a digital version of the secure physical rooms that have long existed for classified information, in some instances on company servers. Through these online rooms, the government would request data, companies would deposit it and the government would retrieve it, people briefed on the discussions said.

The negotiations have continued in recent months, as Martin E. Dempsey, chairman of the Joint Chiefs of Staff, traveled to Silicon Valley to meet with executives including those at Facebook, Microsoft, Google and Intel.