Google, Facebook and Microsoft likely to be most affected.
Online giants including Google, Facebook and Microsoft are likely to face tougher regulations that may force them to adopt clearer or stronger privacy settings, and to be more up-front about what users' data can be used for, thanks to proposed changes to a European Union draft regulation.
German Member of the European Parliament Jan Philipp Albrecht urged that users must be informed as to what happens to their data. "And they must be able to consciously agree to data processing - or reject it," Albrecht said.
Google, Facebook and Microsoft, who were listed among the largest businesses to gain from personal user data, have been opposing such actions in the European Union.
Facebook EU policy head Erika Mann said: "We are concerned that some aspects of the report do not support a flourishing European digital single market and the reality of innovation on the Internet."
In December 2012, image-editing and hosting application Instagram revealed plans to sell users' photos to advertisers, following which it lost nearly a quarter of its users. It subsequently played down the furore and said it had communicated its strategy poorly.