The Heart of Glass singer signed up for Twitter.com in its early days but quit in 2010 after realising updates on her life were so dull it was not worth posting them.
She has since kept her distance from her official online profiles, and now she is convinced there will be a "Luddite backlash" against the Internet and users will start to switch off in droves.
Harry tells NME magazine, "I'm really only concerned with letting people have a certain amount of me - not all of me. I've always fought very hard for a certain amount of anonymity and privacy. I don't participate as much as (bandmate) Chris (Stein) does - I'm very selective... I think that there will be some kind of Luddite backlash. People in general will just all of a sudden unhook themselves. It's such a waste of time."