 And now, great moments in unintended consequences. Part one, net benefits. The year 2012, the problem? Birds are congregating on the Texas Medical Center campus and doing bird things. The solution? Attach nets to the large oak trees on campus, forcing birds to take their business elsewhere. Sounds like a great idea, with the best of intentions. What could possibly go wrong? Turns out, birds eat bugs. With the birds gone, the trees became a haven for cute, furry-looking critters that happen to be North America's most venomous caterpillar. Contact with these toxic misery tribbles can cause intense radiating pain, vomiting fever, convulsions, paralysis, and even death. With nets up and apex predators gone, researchers determined the population of these comb-over pain merchants increased by a whopping 7,300%. Bad news for anyone, but especially a vulnerable population seeking health care at, say, oh, I don't know, a medical center campus. But you know what they say, flock around and find out. Part two, prop comedy. The year, 1986, the problem? Toxins in California. The solution? Proposition 65, a ballot initiative which included a provision making it illegal for businesses to expose individuals to chemicals known to cause cancer or reproductive toxicity without first giving clear and reasonable warning. Sounds like a great idea, with the best of intentions. What could possibly go wrong? When the warning requirements were established in 1988, 235 chemicals made the cut. Today, there are over 900 compounds on the Proposition 65 list, including alcoholic drinks, salted fish, Chinese style, and wood dust. Even cocaine is on the list, so if your eight ball doesn't have a warning label, your dealer is breaking the law. With penalties for non-compliance, including fines of up to $2,500 per violation per day and overzealous litigators looking for their cut, business owners came to the rational conclusion that the cost of a label was less than the cost of litigation. The result? Warning labels everywhere, regardless of the severity of risk or degree of exposure. In bars, restaurants, hotels, spas, ski resorts, schools, and Disneyland. On golf clubs, lamps, toasters, kids' toys, sunglasses, potato chips, pancakes, pumpkin puree, and even trees. These signs have become so common that one study found Californians have learned to simply ignore them. But we don't want to get sued either, so... Warning, this video contains information on Prop 65. Note to the state of California to cause ambiguity between things that are dangerous and things that are harmless. For more information, go to holy crap, this is really not working out the way we had planned.ca.gov. Part three, cold hard cash. The year? 2005. The problem? Greenhouse gases are destroying the planet. The solution? A system devised by the UN Intergovernmental Panel on Climate Change, which rewards companies disposing polluting gases with carbon credits, which can later be turned into cash. The more harmful the gas being disposed, the more credits were rewarded. Sounds like a great idea, with the best of intentions. What could possibly go wrong? Hydrofluorocarbon23, a manufacturing byproduct of the common coolant hydrofluorocarbon22, was seen as particularly harmful, allowing a large number of credits when destroyed. So manufacturers, predominantly in India and China, ramped up production of the coolant, creating more of the dangerous byproduct, which they immediately destroyed, a system that netted the manufacturers tens of millions of dollars a year. Some producers made twice as much from the tax credit than sales of the actual refrigerant. Increased manufacturing of the coolant itself, a contributor of global warming, kept the market price competitively low, discouraging air conditioning and refrigeration companies from switching to less harmful alternatives. When the UN announced a plan to stop the scheme, Chinese producers threatened to vent their huge stockpile of gas directly into the atmosphere, but some activists labeled environmental extortion. Nice climate you've got there. Great moments in unintended consequences, good intentions, bad results. Do you know a great moment in unintended consequences? Put it in the comments, unless we've already covered it. There are 12 of these now.