The paper referenced in the article uses KNN on metadata features to re-identify users from their tweets. They found that account creation time (ACT) alone coul

The paper referenced in the article uses KNN on metadata features to re-identify users from their tweets. They found that account creation time (ACT) alone could get them 97% accuracy. All they did was exchange username for ACT as a unique identifier; and then found that its only ~97% unique.