Thirty years ago in China, you could get in trouble for cursing your cat, because the Chinese word for the pet sounds like the family name of Chairman Mao Tsetung.
Bad-mouthing Chinese leaders in public is still a bad idea today. In private, though, dry and dirty wit is mixing with ancient customs and new technology to give many people a chuckle at the expense of their iron-fisted rulers.
Eavesdrop on a conversation in a taxi, karaoke bar or living room in China's political centre and sooner or later you will hear the latest jibe, often a word play on a leader's name.
A favourite butt of many jokes is Communist Party chief and state President Jiang Zemin. Never far behind is parliamentary chief Li Peng, whom many Beijingers still hate for his role in crushing student-led protests in Tiananmen Square in June of 1989.
None of the humour is aired in the state-controlled media, where political satire is a no-go zone. Instead, people trade gags over tea and cigarettes and, more and more, through the relatively unregulated media of cellphone instant-messaging and e-mail.
Mr. Li's family ties to the power monopoly are a common target.
"Comrades, your skin is black," Mr. Li tells a group of sun-beaten workers in one joke. "Chief, you are even blacker," they answer in a play on the word for black, hei, which also means corrupt.
Jokes about power struggles in the leadership have regularly made the rounds, including one in late 1989 about three leaders who were closely associated with the Tiananmen Square crackdown.
The joke begins with former paramount leader Deng Xiaoping, then-president Yang Shangkun and then-premier Li Peng finding their car blocked by a cow in the road. Mr. Li yells: "If you don't move, I'll declare martial law!"
The cow ignores him.
Mr. Yang yells: "I'll call out the military!"
The cow stares blankly.
Mr. Deng whispers in its ear, and the cow runs off, terrified.
"I said I would name him general-secretary of the Communist Party," says Mr. Deng. (He had already sacked two party bosses at the time.)
Such humour may seem harmless enough, but a commentary in the People's Daily, the Communist Party's mouthpiece, warned cellphone spam mailers in early September that political rumours upset social stability.
On the contrary, some China analysts say, the humour can help a beleaguered population to let off steam.
Ordinary folk have lined their bellies with satire to stomach the side effects of two decades of economic changes, which have spawned iniquities and gross official corruption, the analysts say.
"This leaves huge room for irony, between the way things are and the way things ought to be," said Perry Link, a Princeton University sinologist.
The ironies of modern China -- a portrait of Chairman Mao at one end of Tiananmen Square, the golden arches of McDonald's at the other -- have long captured the imagination of a small group of pop artists.
But, mindful of the censors, they have masked their satire in metaphor and allusion, which limit their mass appeal.
In private spheres, by contrast, punch lines slide off the tongues of cab drivers and shopkeepers.
Prof. Link has documented how China's hoi polloi have recharged the powerful oral tradition of shunkouliu or "slippery jingles," which are often political gripes set to rhythms and date to the Tang Dynasty of 618-907 AD.
Not only have jaded urbanites tuned out the interminable drone of state news broadcasts, they have had a field day parodying socialist-style rhetoric, most recently Mr. Jiang's Three Represents theory on modernizing the party.
"By day, the Three Represents," goes one saying about party bureaucrats. "By night, the Three Accompaniments," a euphemism for the services of nightclub hostesses.
Another joke centres on a meeting between the United States, Russia and China to decide how to deal with Osama bin Laden.
U.S. President George W. Bush suggests blowing him up with three missiles. Russian President Vladimir Putin favours sending three beauties to assassinate him.
Says Mr. Jiang: "Let's bore him to death with the Three Represents."
The question is, how much punch do today's political lampoons pack?
China-watchers debate whether they serve more as a force of resistance to the party or as mere entertainment.
In 1989, such jokes had a serious political edge. Student protesters smashed small bottles -- xiao ping -- in a show of contempt for Deng Xiaoping.
They screamed the Marxist slogan "May Deng Xiaoping live 10,000 years," which sounds the same in Mandarin as "May Deng Xiaoping be smashed to pieces 10,000 times."
But the bloody crackdown on June 4, 1989, and the ban on the Falun Gong spiritual movement a decade later have proven the dangers of public opposition to the party.
In the mercenary 1990s, self-interest reigned and political apathy set in.
Still, the shunkouliu show just how much Chinese need to vent their discontent, Prof. Link says. He compares the sayings to late-night comedy talk shows popular in the United States.
"Bill Clinton and Monica Lewinsky are skewered, and everybody feels sort of elevated to their level by being able to skewer them," he said.
"You let off your steam and you go on with your daily life."