After years of cooperating with the government, the immediate goal now is to thwart Washington — as well as Beijing and Moscow. The strategy is also intended to preserve business overseas in places like Brazil and Germany that have threatened to entrust data only to local providers.

Google, for example, is laying its own fiber optic cable under the world’s oceans, a project that began as an effort to cut costs and extend its influence, but now has an added purpose: to assure that the company will have more control over the movement of its customer data.

A year after Mr. Snowden’s revelations, the era of quiet cooperation is over. Telecommunications companies say they are denying requests to volunteer data not covered by existing law. A.T.&T., Verizon and others say that compared with a year ago, they are far more reluctant to cooperate with the United States government in “gray areas” where there is no explicit requirement for a legal warrant.