If you damage property, you will be held accountable. If you recklessly damage property, it is called criminal damage. Criminal damages as defined by Arizona state law (A.R.S. 13-1602A&B) may be a misdemeanor or a felony depending on the amount of damage. In many cases you and your parents are responsible for paying for damages.
Defacing property is also considered criminal damages. This includes marking, scratching or painting of property that does not belong to you and without the owner's permission. Painting graffiti is breaking the law.
In Arizona, a 16-year old who spray-painted 32 homes, a half-dozen cars, and various garage doors and fences was tried as an adult and sentenced to 2 months in jail and 3 years probation. Juveniles who damage the property of others can be placed on probation (either with or without detention) and can be required to pay for damages.
Laws may have changed since the last time this article was updated. The current and most up-to-date laws can be accessed here.