A Chinese-American woman has been jailed in Los Angeles on charges of spying on the son of Taiwan's president for Beijing — a sign that China's reach now extends into US neighborhoods, and that Washington is pushing back.

• Wanying Zhang, a real estate agent in Irvine, California, was arrested at Los Angeles airport as she tried to fly to China.
• She is accused of tracking Lai Ching-te's son and his family in the US on orders from Chinese officials.
• The charge is acting as an unregistered agent of a foreign government; she entered no plea and was ordered held in custody.
• The FBI called it a brazen plot and part of China's pattern of hunting down critics and officials' families on foreign soil.
• The Justice Department framed the case as a national security matter, saying it will defend the sovereignty of democratic allies.

Outlook: A hearing this week will decide whether she stays locked up while the case proceeds, and more US prosecutions of Chinese surveillance operations are likely.