The United States Refuse Act of 1899 is a long-ignored federal statute. It prohibits all industrial discharge into bodies of water. (source)

The City Council of Chico, California, once issued an edict banning nuclear weapons from the city. Anyone caught detonating a nuclear device within the city limits could face a fine of up to $500. (source)

In Belton, Missouri, it is illegal to throw snowballs. (source)

The principle of habeas corpus (Latin for "having the body"), a fundamental guarantee of personal liberty that ensures that no-one can be imprisoned without a specific charge and a proper trial, was passed into law due to a prank. When England's House of Lords met to vote on the principle in 1679, chances of passage were slim until one mischievous vote-tallier counted the "yea" of a very fat peer as ten votes. No-one noticed the joke or called for a recount, and the Act of Habeas Corpus passed into law. (source)

In Milan, it is against the law not to smile, except during a funeral or hospital visit. (source)

"Time immemorial" is defined as beyond the memory of any living person, or a time indefinitely long ago. However, for the purposes of English law, a statute in 1275 decreed that time immemorial was any point in time prior to 1189, the year when Richard I began his reign. (source)

It isn't true that many of the strange, outdated laws that are still on the books in various jurisdictions are never enforced. In 1999, after falling out of his canoe on the Rifle River in Michigan, a 25-year-old man was convicted for violating an 1897 law prohibiting cursing in front of women and children, and sentenced to four days' work in a child-care program plus a $75 fine. However, the law was struck down by the Michigan Court of Appeals in 2002 and the conviction thrown out. (source)

In Palm Harbor, Florida, it is illegal to have an artificial lawn. (source)

From all levels of government, Americans get 150,000 new laws and 2 million new regulations every year. (source)

It is illegal to drive cattle through the streets of London, England. (source)

In towns in the United Kingdom, it is illegal to fly a kite, use a slide on ice or snow, set off fireworks, or beat or shake any carpet, rug, or mat (except for doormats before 8:00 am). (source)

In the United Kingdom, the government recently considered, but rejected, a proposal to prosecute radical Muslim clerics under a treason law dating from 1351. (source)

In 2004, fisherman Robert Davies was investigated by police in Plymouth, England after selling a sturgeon caught in Swansea Bay. According to a Royal Prerogative passed in 1324, whales and sturgeon caught or washed up on British coastline are to be offered to the Crown. Accordingly, Davies had faxed the Master of the Royal Household and was told to keep the fish, but was unaware it was still illegal to sell. He was not prosecuted and the sturgeon, nicknamed Stan, ended up in the Natural History Museum. (source)

In the U.S. state of Montana, a couple may get married without either being in attendance.

In the U.S. state of Virginia, it is illegal to load or unload oysters from a boat on a Sunday.

In the state of Oklahoma, animal racing is illegal within a mile of a church. (source)

Fortune-telling for money is illegal in the state of Oklahoma. (source)

In Great Britain in the nineteenth century, suicide was a capital offense; if someone survived a suicide attempt, the state would finish the job. (source)

At the beginning of the nineteenth century, at least 222 crimes were punishable by death in Great Britain, including impersonating a Chelsea pensioner, strong evidence of malice in a child 7 to 14 years of age, living with gypsies for a month, damaging Westminster Bridge, (unsuccessfully) attempting suicide, and stealing cheese. In 1861, the number of capital crimes was reduced to four: murder, piracy with violence, treason, and arson in a royal dockyard.