Amazon, Snapchat and AT&T rank among the least trustworthy technology companies when it comes to how they handle government data requests, according to a report from the Electronic Frontier Foundation.

The nonprofit privacy advocacy group released its fourth annual "Who Has Your Back" report Thursday, ranking trustiworthiness of tech companies based on a variety of criteria, including whether they require a warrant for user data and their publication of transparency reports.

Of the more than two dozen companies ranked, Apple, Credo Mobile, Dropbox, Facebook, Google, Microsoft, Sonic.net, Twitter and Yahoo took top honors, earning the maximum six stars in each category studied.

AT&T and Amazon earned only two stars, while Snapchat was awarded one.

A wealth of personal information and data is stored with Internet companies, and concerns over the handling of data have skyrocketed in the wake of disclosures about government spying, as well as cyberattacks and companies' own policies and products.

The report's findings are based on the actions companies take on matters relating to government user-data demands, as well as their stance on transparency. The report was based on publicly available data and records, and did not look at any secretive anti-surveillance measures the companies may have in place. Responses to national security requests cloaked by a gag order weren't factored in either.

Companies were assessed based on six criteria: requiring a warrant for data; telling users about government data requests; publishing transparency reports; publishing law enforcement guidelines; fighting for users' privacy in courts; and publicly opposing mass surveillance.

Following leaks made by former National Security Agency contractor Edward Snowden, more companies have sought to be more forthcoming in how they handle government demands for data. Companies such as AT&T, Verizon and Comcast issued their first-ever transparency reports during the period that EFF examined, and it's partly why major companies like Google and Facebook ranked high on the list.

But others haven't stepped up to the plate as much, according to the EFF. Snapchat earned only one star for publishing law enforcement guidelines, the report said. A Snapchat spokeswoman said the company routinely requires a search warrant when law enforcement comes knocking, but the nature of its service means often there is no content to divulge.

Amazon received two stars for requiring a search warrant and for fighting for users' privacy in courts.

To develop its report, EFF collaborated with the data analysis company Silk to analyze trends in government access requests.

The EFF characterized the report's findings as generally positive. "We saw a remarkable improvement in the areas we've been tracking," said Cindy Cohn, legal director at the EFF, with nearly a year's worth of Snowden leaks helping to lend public attention on the issues.

But researchers also lamented the government's turtle-like pace in protecting users as the technology industry plows ahead. Even more troubling, the government has relied on legal uncertainties to gain greater access to user data, they said.

"Too often, technology companies are the weak link, providing the government with a honeypot of rich data," the EFF's report said.

Zach Miners covers social networking, search and general technology news for IDG News Service. Follow Zach on Twitter at @zachminers. Zach's e-mail address is zach_miners@idg.com