Taiwan's security officials are telling three groups of people to think twice before going to China, as Beijing's new exit-entry rules take effect and searches expand to phones and laptops.

• New Chinese border rules start September 15, with random checks of personal phones and devices expected from October.
• Government workers at every level — police, court staff, even village officials — are seen as targets for Chinese intelligence gathering.
• Religious workers face risk because China requires state religious officials to be present at core rituals, and some Taiwanese believers have been detained while simply visiting as tourists.
• Chip, quantum, special materials and defense industry workers, plus staff at sanctioned firms, face the highest chance of being held or restricted.
• Taiwan's mainland affairs and economics agencies are preparing official guidance on how to protect yourself; many foreign companies already hand out burner phones for China trips.

Outlook: Expect Taipei to publish formal travel guidance within weeks, and more countries to tighten their own China travel warnings as the device checks begin.