Lone drinkers in Wanchai regularly fall victim to being drugged with Rohypnol, GHB or Ambien. It's not a myth. It has happened to 3 of my friends. Most cases aren't reported.

Here some, rather obvious, tips i could think of after reading up online:
- don't bring bank cards, only bring in cash what you're willing to spend
- watch how your drink is prepared
- don't leave your glass unattended
- have a drinking buddy
- make a connection with bar staff
- don't get too drunk
- decline visits to homes of people you don't know well
- cover your glass with a coaster
- raise alarm as soon as you feel different

Also, be aware of what is happening to others around you. Watch out for others.

When you find yourself somewhere unexpected, consider that you might have been drugged. Take immediate action. It might seem you haven't lost anything but maybe HKD100.000 hkd went off your cards, your reputation damaged and you might have damaged something, someone or yourself.
- call your credit card company for last expenditures. Get locations
- have your blood checked for drugs fast at the emergency department of your nearest hospital for proof (later for STDs)
- call 911, even you don't want to bring your case to court to avoid publicity. The police can A)probably help you and B) use your information for profiling, investigation and preventing more cases
- try to find out where you were. Maybe some witnesses are still drinking in the bars. Contact your usual drinking buddies to help out.
- bars usually have CC footage and don't want to be closed down so they should be on your side.

Lot's of reports in HK press, like this: http://www.chinadaily.com.cn/hke ... ontent_15230825.htm
About the practise in Colombia: https://www.youtube.com/watch?fe ... d&v=ToQ8PWYnu04