Ed Poor writes,

But they'd be better off e-mailing a trusted friend on the outside and having their /friend/ post their contributions on their behalf. I have no doubt that even the anonymizing proxies can be backtraced, if some "intelligence service" really wants to make the effort.

It's "likely" (*) that certain oppressive countries maintain anonymous proxies just to see what people do with them. I would never trust an anonymous proxy with anything serious.

(*) for extreme values of "likely"

SS