China's revised counterespionage law took effect Saturday, broadening the scope of what constitutes spying activities to safeguard national security, raising concerns among expatriates and foreign businesses about arbitrary enforcement.

The amended law, which was originally adopted in 2014 to guard state secrets, makes it possible for Chinese authorities to crack down on stealing and disseminating "documents, data, materials and items related to national security and interests."

The revised legislation, which was endorsed at the country's legislature in April, newly covers cyberattacks on state organizations and key infrastructure by "spying entities and their agents" as part of Beijing's efforts to bolster cybersecurity.