Let's say you want to read up on this summer's flooding of the Yangtze River. Or wonder about taking a trip along the Yellow River. Or want to check the lyrics of Cry Me a River. If you are on the mainland, the censors might very well leave you high and dry.
The ever-vigilant authorities went into overdrive this week over the rumours that Jiang Zemin , the 84-year-old former president, had died. According to numerous reports, users of Sina.com's Weibo microblogging platform got 'cannot be displayed' messages when they searched for the Chinese word for river - jiang.
They also found themselves unable to post cartoon pictures of hanging clothes with the trousers hoisted high, a tongue-in-cheek reference to the way the ex-leader liked to wear them.
The Wall Street Journal's website reported that searches were blocked for 'myocardial infarction', hung (a euphemism for death), and '301 Hospital', the Beijing facility where overseas media reported that Jiang was in intensive care.
Why all the secrecy? Yes, we've read the analysts who say that Jiang's death before the 18th party congress late next year would add uncertainty to the transition in which President Hu Jintao is expected to hand over power to Vice-President Xi Jinping .
But Jiang will either be dead - or he won't. Rumours about his being dead cannot make him so. The leadership seems afraid of people talking about Jiang's health. And they seem afraid to issue any facts that would make the matter clear. Xinhua merely said the speculation was 'pure rumour'.