The New York Times wrote April 7, 1998:

"Today's digitally processed words and images may not be nearly as stable or long-lived
[as paper]... From 1976 through 1979, the National Archives worked on recovering certain
1960 census data from tapes designed to run on long-obsolete machines. By the mid-1980's,
computerized land-use maps of New York State produced in the 1960's became unavailable;
the State Archives found that the software required to analyze the data had not been
stored with it and that the hardware and operating system no longer existed... Donald
Waters, director of the Digital Library Federation, a consortium of large research
libraries and archives, said the issue was not merely a matter of technology. 'It's
also legal, organizational and financial,' Waters said.

"That is why Bill Gates's privately held image-bank company, Corbis, 'refreshes' its data
tapes by copying them every few years onto more advanced ones that typically hold more
data in the same space and last longer. Still... of the company's 1.3 million digital images,
50 had been lost because of media failures. The National Archives keeps two copies of its
tapes and refreshes them every 10 years."