Pakistan, June 22 -- At a market stall in Berlin run by charity Topio, volunteers help people who want to purge their phones of the influence of US tech firms. Since Donald Trump's inauguration, the queue for their services has grown.

Interest in European-based digital services has jumped in recent months, data from digital market intelligence company Similarweb shows. More people are looking for e-mail, messaging and even search providers outside the United States.

The first months of Trump's second presidency have shaken some Europeans' confidence in their long-time ally, after he signalled his country would step back from its role in Europe's security and then launched a trade war.

"It's about the concentration of power in US firms,...