From Michael Rubin's LA Times column:
In the aftermath of [Iran's 1999 student] protests, the Chinese government supplied security consultants to Tehran. Rather than bash heads and risk protests and endless cycles of mourning, Iranian security services began photographing demonstrations, after which they would arrest participants over the course of a month when they were alone and could not spark mob reaction.
Googling this comes up with nothing; I can't find a single primary source to confirm this. Of course, it's plausible — probable, even — that China would export its techniques of governmental repression. That's what the CCP would call, "non-interference in the internal affairs of other states".
Until I hear of more evidence though, I'm filing this one under, "Believable, but not verified."
Just learned that Iran accuses international journalists of supporting ‘hooligans’.
http://cnnwire.blogs.cnn.com/2009/06/17/iran-accuses-international-journalists-of-supporting-hooligans/
Wonder if China government teaches them that too.
I believe soon Iran government will display photos of people waving sticks, and claim that the police is maintaining social order.