This is a week that Snapchat probably wishes were over. Days after the mobile messaging app was slammed by government regulators for misleading users about the ephemerality of photo messages, a leading civil liberties organization singled the company out for being particularly weak on privacy.

According to the annual ratings of the Electronic Frontier Foundation, the hugely popular site used by teens to send photo messages that are supposed to "vanish" a few seconds after they're viewed is lagging behind other major tech companies in protecting users' data Relevant Products/Services from the government.

"This is particularly troubling because Snapchat collects extremely sensitive user data, including potentially compromising photographs of users," the report announcing the ratings says.

The advocacy organization rated tech companies based on a series of publicly known characteristics, including requiring the government to get a warrant to obtain the content of communications, alerting users to government data requests, publishing transparency reports about how often they provide user data to the government, publishing their guidelines for dealing with such requests, fighting for users' privacy in court and publicly opposing mass surveillance.

Snapchat only got credit for one category: publishing its law enforcement guidelines.

But the report found that many of the nation's tech companies have changed their ways for the better for consumers following the Edward Snowden leaks about NSA mass surveillance.

Those leaks, the report stated, "repeatedly pointed to a close relationship between tech companies and the National Security Agency. Tech companies have had to work to regain the trust of users concerned that the U.S. government was accessing data they stored in the cloud Relevant Products/Services. This seems to be one of the legacies of the Snowden disclosures: the new transparency around mass surveillance has prompted significant policy reforms by major tech companies."

Apple, in particular, was lauded for making "enormous improvements" -- going from one star last year to a perfect rating of six stars this year.

Among the other tech giants applauded in the report was Yahoo, which was recognized for fighting a legal battle with the Foreign Intelligence Surveillance Court about user privacy. Those proceedings were secret, forcing the company not to talk about them until July of last year.

Facebook, Google and Twitter were also among the companies that received six stars.