“Organisations ‘almost always’ require individuals’ ‘free, specific, informed and unambiguous ‘opt-in’ consent’ in order to make use of personal data they have previously collected in ‘big data’ projects that involve analysing or predicting the ‘personal preferences, behaviour and attitudes of individual customers’, an EU privacy watchdog has said.”
OUT-LAW.com, 9th April 2013
Source: www.out-law.com