Possibly a loose pile of rocks? As it travels down a steep hill.
Television, telephones, cellular devices, and violent video games. They tried to solve the problem by restricting the amount of games they can buy and parents limiting time on devices.
Answer:
The closest thing that I could think of would have to be ODD and/or ADHD
Explanation:
Because with ODD you are pretty much defiant with everybody and practice unsafe behaviors like the ones stated in the question, also with ADHD you tend to act and think like someone who would have ODD.
The 26th Amendment allows those who turn 18 years old, the legal right to vote. So, if we did not have the 26th Amendment, technically speaking, anyone would be allowed to vote at any age. This could render elections unfair, as families with more children than others would have more voting power.