Yet another hunt for Jimmy Hoffa's remains has turned out to be a bust. The FBI said Wednesday it was ending a three-day search after finding no trace of the former Teamster union leader — who disappeared in 1975 — at the site of a long-gone horse-farm barn where a tipster said Hoffa was buried.

The property outside Detroit — the city where Hoffa was kidnapped in a restaurant parking lot — came under scrutiny after Tony Zerilli, 85, the son of reputed former Detroit mob boss Joseph Zerilli, told investigators in January that Hoffa's captors had taken him to the barn, where Hoffa was struck with a shovel and buried alive under a slab of concrete.

Over the years, authorities have chased down tips that Hoffa's body had been hidden at several locations, from elsewhere in Michigan to underneath the end zone at New Jersey's Giants stadium. With the case still cold after 38 years, what should the FBI do now?

For some, that question has a pretty straightforward answer. Debbie Schlussel, echoing opinions expressed by angry citizens, says at her blog that it's time for law enforcement agencies to give up the hunt. The FBI has already wasted millions of dollars on this dig and a previous one several years ago at another farm, Schlussel says, and every dime would have been better spent fighting bigger priorities, like terrorism.

Even if Hoffa's body is found, so what? America shouldn't be wasting yet more money looking for this corrupt union official who was in league with the Mafia, then crossed it...

Hoffa's kids are relatively wealthy. Jimmy Hoffa, Jr. is the high-paid head of the Teamsters Union, and a daughter, Barbara Ann Crancer, is a retired judge with a nice pension (she's now 75). Let them spend the money for this wild goose chase seeking their crooked father's remains. [Debbie Schlussel]

But are Hoffa's alleged mob ties any reason to close the investigation for good? A blogger at The Charley Project, a site about missing persons, says absolutely not.

Yes, Jimmy Hoffa was involved in organized crime — so what? The law is supposed to treat everyone equally. The murder of a drug dealer or mob enforcer is supposed to be investigated and prosecuted with the same zeal as the murder of a prom queen or soccer mom, though I admit in practice that doesn't always happen. [The Charley Project Blog]

Skeptics point out that Zerilli's motives are also pretty questionable. He's selling what he claims is the true story of Hoffa's disappearance — for $4.99 per download or $7.99 per mailed copy. He's even selling pictures of himself for $9.99, or $22.99 with an autograph.

But Hoffa's disappearance is more than a legendary missing persons case — and the butt of jokes on Saturday Night Live. It's also a kidnapping and, presumably, a murder. Dan E. Moldea, author of the book The Hoffa Wars: The Rise and Fall of Jimmy Hoffa, says that means it will never be something investigators should give up on.

"A well-known American citizen — infamous in my book — is standing on a public street in broad daylight, and he vanishes," Moldea tells Today. "That should not be allowed to happen. It happens in some countries, but it should not be allowed to happen in this country. It's one of the great mysteries of the 20th Century."