Since early November, the number of vessels sending the Automatic Identification System (AIS) signal from seas around China plunged by 85 percent. On Oct. 28, more than 100,000 ships were broadcasting but, according to global shipping data provider VesselsValue, by Nov. 17, only 15,000 were broadcasting the signal. The steep decline comes after China's Personal Information Protection Law (PIPL)came into effect on Nov. 1. It requires companies that process data to get approval from the Chinese government before letting personal information leave Chinese soil. China security agencies seized and inventoried a large number self-built AIS base stations along the coastline.