en.wikipedia.org
The classic example of ridiculous pork earmarks is the
Gavina Island Bridge. Said island has a population of 50 people and a small airport for dealing with the surrounding islands, plus a ferry capable of readily carrying cars that services them. A bridge to Gavina needs to be longer than the Golden Gate Bridge and high enough for container ships to go under, and was earmarked for almost 400 million dollars, for 50 people.
Now that's not the real earmark pork. The bridge itself was canceled after much debate over several years. But congress had also earmarked 25 million for a highway to connect to the bridge, and because it was an earmark, that money had to be spent on the highway, funds auto-allocated to the construction company.
Result: There is a major highway in Alaska that goes for many miles with no exits or turnoffs, then suddenly dead-ends at the seashore where it was supposed to connect to a bridge that will never exist. Said highway was built long after the bridge was canceled, because of earmarks to the highway construction company.