Researchers say it is incredibly difficult for information on the Web to be erased, including supposedly private documents and images. For some, there's the threat of cyber-stalking, and for many more, identity theft.
"Once something is on the Internet, it stays on the Internet," said Miriam Simun, research coordinator with the Berkman Center for Internet and Society at Harvard Law School. "All the privacy controls give you a feeling of privacy, and to a degree, they do, but that information can be taken and stored on someone's server. Once it's put out there, you really have no control over it."
In general, Simun says the public should view their sites with what she calls the "80-20 rule."
If a site is correctly protected, 80 percent of the world won't be able to access that information. But 20 percent of the public, if they really wanted to, could access private information such as photographs, phone numbers, addresses or various identification numbers, she said.