[Google engineers] are making it far more difficult - and far more expensive - for the National Security Agency and the intelligence arms of other governments around the world to pierce their systems. As fast as it can, Google is sealing up cracks in its systems that Edward J. Snowden revealed the N.S.A. had brilliantly exploited. It is encrypting more data as it moves among its servers and helping customers encode their own emails. Facebook, Microsoft and Yahoo are taking similar steps. 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. 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. But governments are fighting back, harder than ever. The cellphone giant Vodafone reported ... that a "small number" of governments around the world have demanded the ability to tap directly into its communication networks [and] noted that some countries did not issue warrants to obtain phone, email or web-searching traffic, because "the relevant agencies and authorities already have permanent access to customer communications via their own direct link."