Silicon Valley's role in US government surveillance has triggered public anxiety about the internet, but it turns out there is at least one tech company you can trust with your data. The only problem: it's a relative minnow in the field, operating from offices in Utah.

Xmission, Utah's first independent and oldest internet service provider, has spent the past 15 years resolutely shielding customers' privacy from government snoops in a way that larger rivals appear to have not.

The company, a comparative midget with just 30,000 subscribers, cited the Fourth Amendment in rebuffing warrantless requests from local, state and federal authorities, showing it was possible to resist official pressure.

"I would tell them I didn't need to respond if they didn't have a warrant, that (to do so) wouldn't be constitutional," the founder and chief executive, Pete Ashdown, said in an interview at his Salt Lake City headquarters.

Since 1998 he rejected dozens of law enforcement requests, including Department of Justice subpoenas, on the grounds they violated the US constitution and state law. "I would tell them, please send us a warrant, and then they'd just drop it."

Ashdown, 46, assented just once, on his lawyer's advice, to a 2010 FBI request backed by a warrant from the Foreign Intelligence Surveillance Court.

"I believe under the fourth amendment digital data is protected. I'm not an unpaid branch of government or law enforcement."

Ashdown was wary about Silicon Valley's carefully worded insistence that the government had no direct access to servers. Access to networks, not servers, was the key, he said.

Pete Ashdown has rejected dozens of law enforcement requests, citing user privacy laws.

The state attorney general alleged XMission was soft on crime but the company, with a staff of 45 and turnover of $7m, suffered no official retaliation, said Ashdown. "I didn't feel that I was in danger, or that my business suffered."

In the wake of revelations over National Security Agency surveillance and ties to Silicon Valley he has published a report detailing official information requests, and the company's response, over the past three years.

The Electronic Freedom Foundation called it a model for the industry. "XMission's transparency report is one of the most transparent we've seen," said Nate Cardozo, a lawyer for the San Francisco-based advocacy group.

EFF has lobbied big service providers – in vain – to publish individual government requests and their responses to the requests. Google and other giants would need a different format for scale but could emulate the Utah minnow's spirit, said Cardozo. "The major service providers should demonstrate their commitment to their users and take XMission's transparency report as a model."

EFF's most recent Who Has Your Back report – an annual ranking of privacy protection by big tech companies – gave Twitter the maximum of six stars and just one each to Apple and Yahoo.

Utah is an unlikely home for an internet privacy champion. The state's conservative politicians cheered the Bush-era Patriot Act and welcomed the NSA's new 1m sq ft data centre at Bluffdale, outside Salt Lake City.

Ashdown, who toured the facility with a group of local data centre operators, said he had not received NSA information requests but saw irony in it siting its data behemoth in his backyard.

The agency's online snooping betrayed public trust, he said. "Post 9/11 paranoia has turned this into a surveillance state. It's not healthy."

The only solution to internet snooping was encryption, he said, a point he repeated on a blog.

Ashdown, 46, attributes part of his wariness of authority to his mother, who saw the Nazis overrun Denmark. He ran as the Democratic candidate for the US senate in 2006, promising to bring technology savvy to Washington, but lost to the Republican incumbent, Orrin Hatch. He ran again in 2012, but lost in the primary.

An additional disappointment was the discovery that many if not most ordinary people – at least until the NSA scandal – cared little about privacy when selecting internet providers. "Unfortunately it's not what people think about. They put name recognition and cost ahead of privacy."