
The concept has been around for a while, about 10 or 15 years now, but has in recent years become an IT industry buzzword due to the growth of web-based search, email, retailing, customer relationship management and other services.
Cloud computing is being promoted by large IT companies like IBM, HP, Google, Microsoft, Yahoo and Amazon that have or are planning to build large Internet connected data centres.
With the rise of Web 2.0 applications that are available only on the Internet, a lot of people are uploading data such as emails, photographs and work products to services like Google and social networking websites.
But Stallman sees cloud computing as just a sales ploy that is not in users' best interests.
In an interview reported by The Guardian, he said, "It's stupidity. It's worse than stupidity: it's a marketing hype campaign."
Stallman warns that cloud computing is simply a trap to entice users' into entrusting their data and computing applications to proprietary systems that are beyond their own control and which service providers could make more and more expensive for users over time. He doesn't trust the vendors.
"Somebody is saying this is inevitable -- and whenever you hear somebody saying that, it's very likely to be a set of businesses campaigning to make it true," Stallman said.
He believes computer users should want to keep possession of all their own personal data files and software applications, rather than turn them over to profit driven corporations.
"One reason you should not use web applications to do your computing is that you lose control," he said.
Implicit in his concern is fear for potential loss of privacy and even loss of, or loss of access to, one's data.
An outspoken advocate of software freedom, Stallman continued, "It's just as bad as using a proprietary program. Do your own computing on your own computer with your copy of a freedom-respecting program.
"If you use a proprietary program or somebody else's web server, you're defenceless. You're putty in the hands of whoever developed that software."