At a Rose Parade festival about five years ago, counterfeiters struck Pete Mogannam's deli while passing phony bills at more than a dozen stores in downtown Santa Rosa.
Mogannam's Fourth Street Market and Deli got stuck with a fake $100 bill. He later heard that 13 other merchants also had accepted the funny Benjamins.
"They always manage to get you when you're going 100 miles per hour," Mogannam said of the counterfeiters' method of coming at the busiest times of the day.
U.S. currency has become increasingly difficult to duplicate, with ultraviolet "security threads" and a color-shifting ink technology that was developed in Santa Rosa more than a quarter century ago.
But counterfeiters have also stepped up the sophistication of their craft. In one week in mid-October, the U.S. Secret Service office in San Francisco reported collecting $46,000 in fake currency.
"That's a low week," Special Agent Chip Roberts told a group of merchants last week in Sonoma. The weekly count is typically between $50,000 and $100,000, accumulated in the Bay Area and coastal region from Monterey to the Oregon border.
That may sound like a small hit on the economy, Roberts said. But it involves a large number of fake bills passed and plenty of businesses that suffered losses.
The Secret Service made a presentation Thursday to Bank of the West commercial clients in Sonoma. Stacey Scudder, the bank's Sonoma branch manager, said she wanted her merchants to learn ways to quickly and easily identify authentic currency.
With the coming holiday season, both law enforcement and banks are urging merchants to increase their vigilance for bad bills.
"There's more people out. There's more money changing hands," said Charles White, assistant special agent in charge of the Secret Service office in San Francisco.