▁data ▁to ▁identify ▁individuals ▁is ▁known ▁as ▁data ▁re - ident ification . ▁Success ful ▁re - ident ifications ▁cast ▁doubt ▁on ▁de - ident ification ' s ▁effect iveness . ▁A ▁system atic ▁review ▁of ▁four teen ▁distinct ▁re - ident ification ▁attacks ▁found ▁" a ▁high ▁re - ident ification ▁rate ▁[ … ] ▁domin ated ▁by ▁small - scale ▁studies ▁on ▁data ▁that ▁was ▁not ▁de - ident ified ▁according ▁to ▁existing ▁standards ." ▁ ▁De - ident ification ▁is ▁adopted ▁as ▁one ▁of ▁the ▁main ▁approaches ▁of ▁data ▁priv acy ▁protection . ▁It ▁is ▁commonly ▁used ▁in ▁fields ▁of ▁communic ations , ▁multimedia , ▁bi omet rics , ▁big ▁data , ▁cloud ▁computing , ▁data ▁min ing , ▁internet , ▁social ▁networks ▁and ▁audio – video ▁surve ill ance . ▁ ▁Ex amples ▁ ▁In ▁design ing ▁survey ▁▁ ▁A ▁survey ▁is ▁conducted , ▁such ▁as ▁a ▁census , ▁to ▁collect ▁information ▁about ▁a ▁group ▁of ▁people . ▁To ▁encou rage ▁participation ▁and ▁to ▁protect ▁the ▁priv acy ▁of ▁survey ▁respond ents , ▁the ▁research ers ▁attempt ▁to ▁design ▁the ▁survey ▁in ▁such ▁a ▁way ▁that ▁people ▁can ▁particip ate ▁in ▁the ▁survey ▁and ▁when ▁the ▁result ▁is ▁published ▁it ▁will ▁not ▁be ▁possible ▁to ▁match ▁any ▁particip ant ' s ▁individual ▁response ▁with ▁any ▁data ▁published ▁in ▁the ▁result . ▁ ▁Before ▁using ▁information ▁▁ ▁When ▁an ▁online ▁sho pping ▁website ▁wants ▁to ▁know ▁its ▁users ' ▁prefer ences ▁and ▁sho pping ▁hab its ▁it ▁dec ides ▁to