Hardly a week goes by without someone calling me to complain that a Twin Cities coin dealer ripped them off. Most of the callers are elderly. Many lack any records of their transactions. Some say law enforcement -- the FBI, local police -- advised them to lick their wounds and move on.

Individually, these consumers didn't lose enough to warrant federal attention, and local cops don't have long enough arms to reach across state lines. Hiring an attorney would cost more than they'd hope to recover.

Eventually, they discover "Shortchanged: Ex-cons make a killing in coins," an investigative series the Star Tribune published last year about unsavory characters who work the phones for some Twin Cities coin telemarketing firms. So they call me to find out how they can register a complaint. I pass along the names of federal investigators who've taken an interest in such cases, but I caution against getting their hopes up.

Cops say they've known about rampant fraud in the industry for decades.

The wheels of justice grind slowly, but things may be coming to a head. Last week, Excelsior resident David Marion was indicted by a federal grand jury for allegedly bilking clients of his defunct coin firm, International Rarities Corp., out of $2.7 million. Several other cases are in the works.

Consumers and honest coin dealers ask what's taken so long?

The answer: These cases are complicated, expensive and hard to prove, especially when they involve elderly buyers with spotty memories and incomplete records.

Several salesmen have told me that the industry has become so corrupt, they're getting out altogether. Some say they'd welcome legislation to bring the largely unregulated industry to heel. Others note that the securities industry is heavily regulated yet shares many of the same problems.

Regardless, the best protection may be "caveat emptor" -- buyer beware.

Dan Browning • 612-673-4493