When it comes to ensuring customers get their money back when a broker tanks from fraud or a down market, the safety offered by the Securities Investor Protection Corp. (SIPC) may have more holes than cheese, critics told a Senate hearing Wednesday.

Republican Sen. David Vitter of Louisiana charged that most victims who ask SIPC for restitution come away empty-handed with their retirement savings gone.

“When push comes to shove, SIPC will deny their claims for customer protection,” he said. “Only the lucky few who can find their way into a court with the right kind of experience in these complex transactions has any hope of relief.”

By law if a brokerage fails, SIPC is supposed to get investors back up to $500,000 in securities and cash.

Sigmund Wissner-Gross, an attorney who has battled the agency in court (often unsuccessfully) for retail investors, said financial advisors should warn customers they can take little comfort in the SIPC “Good Housekeeping Seal of Approval” logo that appears often on broker letterheads, websites, e-mails and water bottles.

“If I was an advisor, I’d tell clients to be leery of investments where the broker is selling some non-traditional form of investment to the client, since SIPC only covers very specific types of investments,” Wissner-Gross said.

He also said customers should be warned never to loan money to a broker-dealer because SIPC only covers losses from securities clients have bought.

It was SIPC’s successful contention in court that it did not owe any money to the reported 28,000 investors bilked out of more than $7 billion from jailed financier Allen Stanford. That was because the money was technically given to him as loans rather than to purchase securities.

Wissner-Gross noted that he had to fight tooth and nail, several years before Stanford’s downfall in 2009, to get money from SIPC for hundreds of investors defrauded by another Ponzi scheme. That one was operated by a Long Island broker who told investors the money would go into mutual funds or into what turned out to be a nonexistent money market fund. One of the investors was a Holocaust survivor.

“Even after ‘customer’ status was recognized, the SIPC-appointed trustee vigorously fought individual customers on establishing their losses,” said Wissner-Gross. “The defrauded customers were bewildered and frustrated that, at every step of the way, we had to battle the trustee.”