A new law that went into effect on January 1st in Illinois attaches specific legal penalties to wheelies. Pull a wheelie once, while exceeding the speed limit, and the minimum fine attached to that specific offense is $100. Twice: up to $1,500 and six month in jail. Three times? $2,500 and a year of hard time.
Illinois Senate Bill 3452, which was passed last July, address various actions and parts related to motorcycle safety. It also becomes an offense to remove both hands from the handlebars while the bike is in motion or to fit handlebars that reach higher than the rider's head. No more ape hangers. Much of the bill though focusses on stunting, in addition to those wheelies, it also bans the practice of sitting or standing on any part of the motorcycle that's not the actual seat.
In the law, a wheelie is defined as, "operating a motorcycle, motor driven cycle or moped on one wheel." Presumably, the same penalties are then attached to stoppies.
In most places, a wheelie just falls under the generic "reckless driving" catch all along with other nebulously defined offenses like driving/riding in a dangerous manner. The Illinois law is remarkable in attaching specific penalties to wheelies.
Embedded below is the complete text of SB 3425.