http://en.gmw.cn/2014-05/27/content_11440792.htm

One of my predictions is coming true. Some of you may remember that predicted a crackdown over the course of 2014 in regards to general naughtiness by foreigners in general, whores and drugs being the two big things that could get people in trouble.

Sure, these guys were some of the crazier ones, dealing in ice (Crystal Meth), but remember that the Chinese will probably not differentiate too much between a meth fiend and a harmless stoner.

People may have consider being squeaky clean in regards to their behaviour these days. This is a PR thing to destroy the image of foreigners as a whole in China, it seems.