The number of German tourists visiting the US has significantly decreased since Donald Trump's second term began, with reports of detentions at the border due to immigration policy changes. Travel agencies noted a 50% drop in bookings compared to the previous year, although no cancellations have occurred yet. Tourists are advised to back up their data, be cautious with their devices, and prepare for potential detentions. Specific cases highlight the risks of carrying certain items or having critical messages on phones. Travelers are encouraged to memorize important contacts and ensure they have funds for emergencies.