It is illegal to damage or deface someone else's property.  As long as the damage caused is under $1,000 worth, the offense is a misdemeanor and is punishable by up to $500 in fines and 30 days in jail.  If the damage caused is $1,000 or more, the offense is a felony punishable by a fine and up to 5 years in jail.  In addition, anyone who vandalizes someone's property will have to pay for the damages that they caused. 

S.C. Code Sections 16-11-510, 16-11-520, and 22-3-550.