The Wisconsin Credit Union League, which represents 360 credit unions around the state, warned that "scam artists are ripping people off by preying on consumers' concerns about the millennium change. Don't get taken!"
The warnings have circulated for nearly two months, generating dozens of news reports around the world.
But there have been few, if any, cases reported. The FBI, the Secret Service, the Federal Trade Commission, the American Bankers Assn. and even the Wisconsin group knew of no one who had actually been called.
The Canadian Bankers Assn. said it was aware of one case but provided no details.
"If it had reached a certain level of cases, the field offices would have notified us," said FBI spokeswoman Jule Miller. "That's not to say the local field offices haven't seen a case, but there is no epidemic."
Det. Sgt. Barry Elliott of PhoneBusters, Canada's national clearinghouse for telemarketing fraud, said that even without a case, it was worth issuing a warning on Y2K bank scams since it was plausible and people are so worried that they could easily fall for one.
Sharon Wilks, a spokeswoman for the Canadian Bankers Assn., said the group's alert also helped allay fears about the banking industry in general.
"Quite honestly, one of our greatest concerns was having someone running around saying that the banking industry wasn't ready," she said.