One of the tech world's greatest lawyers told me the other day that he thought the retweet was the greatest way of saying something truly nasty about another person without having to write it yourself.

However, some authorities are, perhaps, becoming wise to this secondary insult market.

According to UPI, Cheng Jianping, a human rights activist in China, retweeted something written by her fiance on Twitter. His tweet was a slightly sarcastic note concerning supposed Chinese nationalists who had decided to smash up Japanese products because of a dispute between China and Japan over the East China Sea islands of Diaoyu/Senkaku.

Her fiance, Hua Chunhui, had reportedly tweeted: "Anti-Japanese demonstrations, smashing Japanese products, that was all done years ago by Guo Quan (an activist and expert on the Nanjing Massacre). It's no new trick. If you really wanted to kick it up a notch, you'd immediately fly to Shanghai to smash the Japanese Expo pavilion."

This is more than 140 characters when translated into English. But, even in English, one can feel the sarcasm.

Cheng reportedly managed to add a couple of words to her retweet, just to reinforce the joke: "Charge, angry youth!"

Sadly, this retweet has reportedly disappeared from her Twitter feed. She and her fiance were each detained last month, but Hua was released five days later, according to a New York Times story. Hua told journalists that he and Cheng were supposed to get married the day they were detained. Cheng was subsequently sentenced to a year's hard labor in the Shibali River women's labor camp in Zhengzhou city in Henan Province.

Twitter is actually banned in China, but enterprising Chinese seem to have found many ways to obviate this stricture.

And lest we think that a lack of humor might somehow be confined to the at times draconian Chinese regime, there is the case of Paul Chambers to remember.

He is the Brit who sarcastically tweeted that he would blow up his local airport if the staff didn't clear it of snow. He was found guilty and lost his appeal last week.

The authorities are monitoring your jokes, people. You have been warned. Tweeting is no laughing matter. Neither, it seems, is retweeting.