Get collared years ago on a bogus drug charge because the oregano in your back pocket looked like was a bag of weed? Or maybe a judge back in 2006 dropped those charges because you were able to provide proof for that Adderall prescription? Under proposed legislation, it will not matter if you were innocent all along or even proven innocent by a court of law.

Either way, you can forget about buying a gun.

The Fix Gun Checks Act of 2011 would greatly expand the definition of those legally prohibited from owning firearms to include anyone who’s ever been arrested — even if never convicted or found guilty — for drug possession within a five-year period. The legislation is certainly troubling for those who want a “common sense” debate about drug decriminalization. And it would seem fears that any new national gun-control legislation would be used to limit the gun-rights of law-abiding citizens is at least partially justified.

Sponsored by New York Democratic Sen. Chuck Schumer and introduced earlier this month, the expanded background checks bill includes a “clarification of the definition of drug abusers and drug addicts who are prohibited from possessing firearms.” Under Schumer’s bill, the definition of a “drug abuser” would include anyone with “an arrest for the use or possession of a controlled substance within the past 5 years.”

Current federal law already specifies that two kinds of drug users can be barred from owning a gun: (1) Those who have been convicted of possessing or using a controlled substance in the past year and (2) Anyone who has had multiple drug arrests in the past five years, including one within a year of applying for a firearm, according to the Bureau of Alcohol, Tobacco and Firearms.

The rules surrounding what “inference” the federal government can make about a current “drug user” are complicated. Add to that regulations stating who is prohibited from owning a firearm; a cumbersome background check system; and inter-departmental communication and, suddenly, the combination of firearms and drugs becomes a confusing bureaucratic mess of regulations and codes.

But the “arrest” language of Schumer’s bill and a clarification from the ATF indicate that a greater number of innocent Americans would be barred from owning a gun if the Senate bill becomes law.

“Under the definition of ‘unlawful user’ … an inference of current use could be drawn if the one arrest resulted in a conviction for use or possession of a controlled substance within the past year,” the ATF told the The Daily Caller.

To clear up any confusion, Schumer’s bill would expand that “inference” to say: if you’ve ever been arrested for any kind of drug use or possession in the past five year, you can be denied the lawful possession of a firearm.

The bill’s definition of an “unlawful user” also includes anyone arrested for drug paraphernalia within the past five years if the paraphernalia is found have traces of a drug, and those who make an “admission” to using or possessing a controlled substance in the past five years. The meaning of “admission,” however, is not defined.

Schumer’s office was unavailable for comment. One thing is clear, though: the senator’s legislation would prohibit a lot more innocent-until-proven-guilty people from possessing firearms.

A little more than 1,600,000 people were arrested in 2009 on drug violations, according to statistic from the Federal Bureau of Investigations. About half of those people were arrested on marijuana charges, with simple drug possession — rather than sale or manufacturing — accounting for nine-tenths of those collars, according to Reason magazine. It’s those last set of figures that could very well rally two groups most people might consider odd bed-fellows: pot-smokers and firearms enthusiasts.

Aaron Houston, director of government relations for Students for Sensible Drug Policy, said adding even more penalties to those thousands of people arrested for marijuana “doesn’t do anything to solve the problem.”

“It makes criminals out of law-abiding Americans. Clearly, [similar drug policies] have not worked up until now,” said Houston. ”Heaping criminal penalties onto otherwise law-abiding Americans just because they possess a little bit of marijuana is a failed policy.”

The SSDP doesn’t have an official position on the Fix Gun Checks Act of 2011, but Houston said that if the “arrest” language was removed, the group “certainly wouldn’t find it as problematic as we do now.”

The current National Instant Background Check System (NICS) only requires a check on those purchasing a firearm from a licensed dealer. Gun-control advocates have pushed for those checks to include guns exchanged between individuals, which is often referred to as the “gun show loophole.” The addition of Schumer’s drug legislation plays directly off public fears that accused Tucson shooter Jared Loughner —  apart from allegedly being determined to kill no matter wat — also admitted to using marijuana. No research, however, has proven a causal link between marijuana use and violent acts.

New York Democratic Rep. Carolyn McCarthy is expected to introduce a companion background check bill  — modeled after Schumer’s — in the House very soon. Houston called Schumer “terrible on this stuff,” and expressed dismay that McCarthy would include similar language in her bill. McCarthy’s office said it was moving forward carefully but wants to ensure that “the most dangerous people who shouldn’t be allowed to buy guns are in the NICS database.”

“Everyone agrees on the goals of the bills to require a background check for every sale and to make sure more names of people who should be in the database are actually put into the database,” said a spokesman for McCarthy. “As for any more specifics, that’s being discussed.”

Even the nation’s largest gun-control advocacy group, the Brady Campaign to Prevent Gun Violence, has problems with Schumer’s drug language.

“It’s a concern we’ve raised about this proposal, too. I’ve got the same concerns,” said Paul Helmke, president of the Brady Campaign. “[There is] the whole innocent-until-proven-guilty concept coming into play here. So that alone is a legitimate concern.”

Helmke said the Brady Campaign was working closely with McCarthy’s office, noting that the representative’s legislation hasn’t even been introduced yet.

“It’s not going to be introduced after this recess week, and they’re going to be making some changes,” said Helmke.

Email Jeff Winkler and follow him on Twitter