It was among the most frightening phone calls Don Bodiker ever received. A stranger calling from California was reading Bodiker's tax return.
"We had not even sent our taxes in yet," he says. "They had not even been mailed."
And worse, the stranger got the tax return online straight out of his computer, "where he could read every single line of everything that I had on my taxes," says Bodiker.
It was, he says, "a very scary moment for us."
It's all there, he says – tax files, checking account and routing number.
As CBS News Correspondent Wyatt Andrews reports, file sharing today is the rage on the Internet, mostly because of users who want to share songs. But because file sharing literally opens your computer to outsiders it can also lead to snooping. All Jeff does is search for the word "tax."
Millions of Americans now share files, usually music, by downloading what's called peer-to-peer software. The problem is many users don't understand which files exactly are being made public.
While we watched, Jeff pulled the tax return of Zachary in New Mexico and called him
"You had your refund of $794 sent directly to your checking account," Jeff tells Zachary. "No sir I am not kidding."
Zachary, clearly shaken, agreed to speak with CBS News.
Asked to share his thoughts about it, Zachary says: "I'm deeply concerned, and I think something needs to be done now. "
After tracking down Zachary, it's learned that both he and Bodiker had installed a file share program called BearShare. They had no idea BearShare was giving away personal documents like their taxes.
Zachary says the software program didn't give him enough warning that he was giving away personal information.
"If I had known that I never would have downloaded the program," he says.
The makers of BearShare declined comment but an industry spokesman, Adam Eisgrau, says the privacy rules for Bear Share will be upgraded immediately.
"As I understand it, a new version will be coming out literally in a matter of days that will seek to close any possible vulnerabilities of this," says Eisgrau.
And there are plenty of vulnerabilities. Besides tax returns, CBS News also found private medical files, and private bank statements.
Jeff doesn't believe both Bodiker nor Zachary meant to share their tax returns.
Jeff says computer users need to be more responsible for what they allow on their computer and need to know what a program does or can do. Otherwise users in such a rush to take in music files, may well be giving away much, much more.