Katya’s phone suddenly refused to provide the basics she needed to drive home to Moscow from St. Petersburg. She, her partner and countless others were unable to go online, cut off from their apps for things like maps, banking, paying road tolls and buying fuel.

There was no warning, no hint how widespread the outage was, no clue how long it would last — but it wasn’t a surprise, either. Russia’s mobile internet networks now have frequent blackouts because of the war with Ukraine.

Since last month, the authorities have shut those networks down every day in various parts of the country, in unpredictable patterns, for hours at a time. The goals is to try to thwart attacks by Ukrainian drones that use mobile connections for navigation.

It is a big disruption in a country where smartphones provide the only online access for millions of people. The government regularly touts an array of online services, like filing tax returns and applying for jobs, and President Vladimir V. Putin claimed this year that Russia was “a step ahead of many other nations.”

Even so, “they can turn off the internet,” said Katya, 32. She described how the government had encouraged reliance on apps and web services — and then exercised control over internet access — as a “digital gulag.” Like others interviewed, she asked to be identified only by her first name out of fear for her safety.

She and her partner made it home from their recent weekend getaway, after struggling with a partially downloaded map and phoning her partner’s mother to top up their debit card to pay for gas.