Ten days ago, another case of Chinese espionage came to a tentative end. Three Chinese nationals, who were arrested for spying, received varying prison sentences.

The three individuals had been caught illegally photographing the U.S. Naval Air Station in Key West, Florida, on two separate instances in December and January.

During the first instance, Lyuyou Liao entered the base and photographed and recorded sensitive military equipment before he was arrested. For his actions, he received a one-year prison sentence followed by a one-year supervised release.

Then, in January, Jielun Zhang and Yuhao Wang were arrested for photographing military and naval infrastructure inside the base. They received a one-year and nine months of prison sentences, respectively, followed by a one-year supervised release.

This is yet another instance of Chinese espionage in the U.S. Last year, two Chinese men (one purportedly an intelligence officer) attached to the Chinese Embassy drove straight into the Joint Expeditionary Base Fort Story, Virginia Beach. They were quickly stopped by the base’s military policemen.

Naval Special Warfare Group 2 (NSWG 2) units regularly hone the marksmanship skills at Fort Story. Navy SEALs from the East Coast teams (SEAL Team 2, SEAL Team 4, SEAL Team 8, and SEAL Team 10) will do the 20-minute drive from their home base of Little Creek to practice.

Then last February, the FBI announced that it was looking for a Chinese Army officer who studied in the U.S. under the alias of a foreign student in order to access sensitive technical and scientific information. According to the FBI, the 29-year-old Lieutenant Yanqing Ye lied about being in the Chinese military, and more specifically in the National University of Defence Technology.

One of the primary aims of Chinese espionage efforts is to steal technological advancements of other countries. To achieve this, Chinese intelligence officials rely on both Human Intelligence (HUMINT) and Open Source Intelligence (OSINT).