I tried several words, they are not blocked. Maybe it's because the government is loosing some of the restrictions, which seems to be true in the last few months. Usually political sensitive contents on Renren (RENN) were blocked within a few hours, but now they are "allowed" to be there, for now. My favorite blocked word was "Tomorrow", which was blocked during Feb 2011 when "Arab Spring" spread to China, so that people could't say things like "let's go on the street tomorrow", lol, of course, it's not blocked now.