When San Francisco banned giving away toys with happy meals that exceeded a certain percentage of fat, McDonald's responded by offering the toys with purchase of a happy meal and a 10 cent contribution to charity. They also stopped selling the toys without happy meal purchase, meaning you now have to buy the meal to get the toy. http://www.businessinsider.com/mcdonalds-happy-meal-law-loophole-san-francisco-2011-11

Back when hotels were struggling with explosion of dial up traffic, many implemented a $1 surcharge on local calls. The hope was to deter calls.

Instead, where people previously would check email and logoff, they started keeping the line open indefinitely to avoid subsequent $1 charges. This ended up putting much more stress on the phone systems. (When AOL had issues with busy signals, people would likewise line camp, exacerbating those issues.)

Colorado tried to use affiliates to create a taxable nexus for sales tax purposes. Rather than subject all Colorodans to sales tax, Amazon got rid of Colorado affiliates. Not only did Colorado not get the sales tax revenue, they lost income tax for those affiliates.

This doesn't always backfire. New York passed a similar law and Amazon still has affiliates there.

The essential air service program was designed ostensibly to bring air service to rural communities. It subsidizes airlines for flying unprofitable routes. in order to get the subsidy, carriers must fly. Often they will fly empty planes back and forth. Not only does this waste money, it is terrible for the environment. it also exacerbates congestion at hub airports.

The higher termination fees for rural phone companies were supposed to offset higher costs of operating in rural areas. Instead, these companies have exploited the system to offer free conferencing services, free international calls, etc. Customers in cities end up subsidizing these services that weren't the purpose of the program.

Use-it-or-lose it budget policies ostensibly lead to more efficient distribution of company resources. In reality, it's not uncommon for managers to blow year end budgets on frivolous purchases so that they don't lose it next year.

Password policies which require people to use mixed case, special characters, numbers, not vary old passwords, etc. Passwords that follow these rules are theoretically more secure. But because people can't remember them, they write them down or store them in a text file - both of which are less secure than letting the user pick a password he can remember.