Abstract: A stochastic privacy service provider may provide users with a guaranteed upper bound on a probability that personal data will be accessed while enabling the services to collect data that can be used to enhance its services. Users may receive incentives to become participants in a stochastic privacy program. The stochastic privacy provider may employ one or more probabilistic and decision-theoretic methods to determine which participants' personal data should be sought while guaranteeing that the probability of personal data being accessed is smaller than the mutually agreed upon probability of access. The probability of access may be on a per time basis. The stochastic privacy provider mayaccess coalescenses of the personal data of sets of multiple people, where a maximum probability is given for accessing statistical summaries of personal data computed from groups of people that are of at least some guaranteed size.