Communications firms are being asked to record all internet contacts between people as part of a modernisation in UK police surveillance tactics.
The new system would track all e-mails, phone calls and internet use, including visits to social network sites.
Ms Smith said that while the new system could record a visit to a social network, it would not record personal and private information such as photos or messages posted to a page.
"Ministers are making a distinction between content and communications data into sound-bite of the year. But it is spurious.
"Officials from dozens of departments and quangos could know what you read online, and who all your friends are, who you emailed, when, and where you were when you did so - all without a warrant."