A privacy attack is the exploitation of an opportunity of someone to identify a study participant based on public research data.[1] The way that this might work is that researchers collect data, including confidential identifying data, from study participants. This produces an identified dataset.[1] Before the data is sent for research processing, it is "de-identified", which means that personally identifying data is removed from the dataset. Ideally this means that the dataset alone could not be used to identify a participant.[1]