Though I'm only surmising, after reading some pages about China and tricycles via Google, they're probably either 'unlicensed business' or weren't paying the trike tax.
Seems pretty silly, though.
http://www.bikechina.com/ct-pscchina-6.html
http://www.cyberdyaryo.com/local/le2001_0607_01.htm
http://cms.westport.k12.ct.us/cmslmc...inginchina.htm