Forrester has been analysing the anonymous login and granular data sharing announcements made by Facebook last week and believes they will lead to less information becoming available for marketers. Anonymous login and users ticking off the level of data an app can find out about them will improve privacy if these are optional, but will have a major impact on marketers if the moves are mandatory, Forrester concludes. It could mean marketers need to use a third party for profiling audiences on the social media network.