SPRINGFIELD, IL—With the state legislature's passage of a bill last week allowing police officers to cite Led Zeppelin bumper stickers as probable cause for a vehicular search, Illinois became the 13th state to recognize classic-rock-related automobile decorations as grounds for waiver of a warrant.

"We've known for years that there was a direct correlation between the presence of a Led Zeppelin bumper sticker and the likelihood of that vehicle containing a controlled substance like marijuana," said DeKalb County Sheriff Ronald Bauer. "However, it wasn't until last Thursday that it was within our power to act on this knowledge to make a drug-possession arrest."

Illinois' action comes on the heels of the recent Supreme Court decision that the Fourth Amendment guarantee against unreasonable search and seizure does not require police to obtain a warrant if there is sufficient cause to believe the vehicle contains contraband.

Following the top court's ruling, a number of states, including Utah, North Carolina and Wisconsin, moved to specifically name Led Zeppelin bumper stickers as a factor in determining whether to conduct searches.

The decision, says Bauer, is supported by extensive data. Illinois state records show that in 1998, there were 362 cases in which a traffic-violation-related search of a Led Zeppelin-logo-adorned vehicle was found to contain illegal drugs or such drug paraphernalia as rolling papers, plastic baggies and metal pipes bearing a row of four cryptic symbols.

Yet before the passage of HB 1921, ill-defined definitions of probable cause have meant that an officer acting on this knowledge was entering risky legal territory.

"This is exactly what policemen have been asking for for years," said Bauer, who said the new law will precipitate a "considerable increase" in the frequency of drug-related arrests of motorists by Illinois police, especially in rural areas. "It used to be that if we spotted a car with that crazy-looking wizard on it, we had to just drive right past unless the longhairs inside were specifically doing something illegal."

Illinois Attorney General Jim Ryan applauded passage of the bill.

"After the Supreme Court decision, it was just a matter of fine-tuning our interpretation of 'probable cause,'" Ryan said. "We've found that Led Zeppelin bumper stickers—or, for that matter, just the sound of "The Immigrant Song" or "Livin' Lovin' Maid" coming from an open window—is exactly the sort of smoking gun local authorities needed to establish a baseline for assessing that probable cause."

Ryan continued: "When it comes right down to it, though, prudent officers have always, to a great degree, relied on common sense. If a vehicle, especially a late-'70s American-made sedan with a vinyl top and some rust, also bears a Led Zeppelin sticker, what are the odds the driver is not in frequent possession of drugs or alcohol?"

Preliminary data seems to indicate that this logic is sound. In a Monday-afternoon field test, state troopers detained 100 Peoria-area motorists under the new Criminal Code 861.4/Section 8 (Probable Cause/ZOSO). Nearly 60 percent of the vehicles contained alcohol, drugs or drug paraphernalia, and nearly all contained suspected alcohol or drug abusers.

Rockford resident Doug Wojcek, charged Tuesday with possession of a quarter-ounce of marijuana, was among those arrested under the new law.

"I was minding my own business when some policeman pulls me over and searches my glove compartment," said Wojcek, 36. "It was just like when Robert Plant gets hassled by the cops in that one song 'Misty Mountain Hop.' Hey, what could I do?"

"This is bullshit," he added. "What about the kids with those Nine Inch Nails stickers? No one is going after them."

Despite such complaints, Illinois Gov. George H. Ryan spoke out in support of the law and advocated widening its scope.

"We might have to add provisions for the search of vehicles bearing the Pink Floyd rainbow-and-black-prism, the Blue Öyster Cult symbol, or maybe even the word Ozzy," said Gov. Ryan, noting that many other states had already made these changes. "We cannot allow this law to become discriminatory in practice. It must serve everyone equally."