HUNTINGTON, N.Y. (CBSNewYork) — A Long Island dentist says he is the victim of a mistaken-identity nightmare.

As CBS2’s Carolyn Gusoff reported, the pediatric dentist shares a name with another pediatric dentist in Florida who is accused of harming young patients.

There’s Long Island’s Dr. Howard W. Schneider, and there’s Dr. Howard S. Schneider in Jacksonville, Florida, who is accused of horrendous treatment that apparently spurred the public outrage and class action lawsuits alleging he strapped children down and unnecessarily pulled mouthfuls of teeth.

A thousand miles away, Long Island’s Schneider feared the mix-up would ruin him.

“It was horrible,” he said. “I couldn’t sleep for three days.”

After Schneider’s office in Huntington was besieged with threatening calls, employees now answer the phone saying, “Hello, this is Dr. Howard Schneider’s office of Huntington, Long Island, not of Jacksonville, Florida.”

“It was horrible,” Schneider said. “It was things like somebody said they were the FBI; they were going to bomb our building. … ‘I wish everybody in your family dies of cancer.'”

“Vulgar language beyond belief, death threats,” said hygienist Allison Resnick.

Schneider quickly figured out he was living an extreme case of mistaken identity.

He fought back online, replying to every single attack message, telling people: “Thank you for writing. This story is not about me. We don’t do things that way.”

Howard Schneider in Florida has reliquinshed his dental license and closed his practice.

Experts warn the mix-up is a cautionary tale.

Digital experts at EGC Group say if you have a common name and a business, it’s critical to differentiate who you are and where you’re located online.

“Register a domain with your name,” said Nicole Larrauri, managing partner of EGC Group. “Make sure you get it before somebody else does, especially if you have something that’s somewhat common.”

Long Island’s Schneider said there’s a silver lining: His Facebook page is now filling up with messages of support.

Howard Schneider in Florida has repeatedly denied wrongdoing.