Parents hire private investigators to keep an eye on their student children
Rich parents, often from the mainland, hire private detectives to find out if their student children are mixing with the wrong crowd

Last year, a few weeks into the summer, a mainland University of Hong Kong undergraduate told his parents that he was not going home for the summer break. Then he stopped calling. He was never available for online video chats. His parents started to panic. They feared the young man had slipped into a world of drug-fuelled parties.

The detective did, for a week. From the flat above, he watched and listened. He dropped a piece of clothing onto the student's balcony to have an excuse to peek inside the flat and film. The detective knocked, equipped with a Bluetooth earpiece with a tiny camera. He braced himself for the wild party inside.
Inside a few clean-cut young men gathered, the room filled with guitars and drums. There were no pills, no bongs. For a few more days Liu stalked the group and soon his suspicions were confirmed. "Every day they didn't do anything other than band practice or going to the beach,'' Liu said. "Nothing bad."
As more mainland parents send their children to Hong Kong to study, a growing number of those who are wealthy - and suspicious - are paying detectives thousands of dollars to monitor their children. The targets range from kindergarten students to doctoral candidates, and share the background of being scions of prominent families travelling far from home to study.
Detectives say they employ a wealth of techniques - from planting cameras in water bottles to infiltrating students' social circles - to learn their targets' routines. While some parents fear that their children are experimenting with drugs or skipping classes, some detectives discover that their students' secret desires are as benign as becoming rock stars.