There's scarcely a dorm room in the land that hasn't displayed a stolen traffic sign at some time or another. Yet what seems funny at the time can get you into serious trouble. Stealing or interfering with street signs is a criminal offense in most states, punishable by fines, community service and even jail time. Thanks to the legal remedy of restitution, you'll also face a hefty repair bill.
TL;DR (Too Long; Didn't Read)
Theft of a street sign is a misdemeanor in most states. It carries a fine based on the value of the sign, and up to around a year's jail time.
If You Can't Do the Time, Don't Do the Crime
Though it may seem like a prank, traffic sign theft is actually just the crime of theft. In most jurisdictions, the severity of the punishment depends on the value of the item stolen. Street signs can run anywhere from $50 for a simple cone to upwards of $500, and you'll have to pay that amount as restitution in addition to the fine. If that doesn't seem like much, know that in New Jersey, stealing a sign worth more than $500 can land you fines of up to $15,000 and five years' jail time.
Risk of Injury Means Harsher Penalties
In most jurisdictions, you'll face a harsher penalty when your actions could result in injury or death. Stealing a stop sign, children-at-play sign or railroad crossing sign, for example, could result in a fatal accident. Now, you may be facing criminal injury charges all the way up to felony manslaughter which carries a maximum 20-year prison sentence. The victims may also have the right to sue you in civil court if they can show that the accident would not have occurred but for your sign theft.
Damaging the Sign Means a Vandalism Charge
Vandalism is a broad category used to describe a variety of offenses. The common thread is some type of property destruction, such as breaking the supporting post when stealing a "No Parking" sign. Some states refer to this type of crime as "criminal mischief" or "malicious mischief," and there are various degrees of the crime based on how much damage you've caused. The punishment for vandalism is usually a fine and restitution, but it might also include probation, community service and incarceration. Some states have harsher penalties for vandalism to public property – a category that includes street signs.
If You Really Want a Sign, Buy One
Even if you haven't stolen anything, the simple act of possessing a traffic sign or having it on display is illegal in some states, punishable by fines and incarceration. There's generally no penalty for possessing "retired" signs, so your safest bet is buying a sign that's been taken out of circulation. The City of Seattle, for example, regularly sells off its retired street sign inventory for as little as $5 per sign. The money goes back into the public purse, so everyone wins.