No person shall without lawful authority attempt to or in fact alter, deface, injure, knock down, or remove any official traffic-control device, or any railroad sign or signal or any inscription, shield, or insignia thereon, or any other part thereof. Every person who is convicted of a violation of this Section shall be guilty of a Class A misdemeanor, punishable by a fine of at least $250 in addition to any other penalties which may be imposed.
625 ILCS 5/11-311
Interference with official traffic-control devices or railroad signs or signals
P.A. 83-672.
Official source: Illinois General Assembly. Reproduced from public-domain Illinois statutes; confirm against the official source for the current text. Not legal advice.