We examine the effect of social trust on a network in which agents communicate with each other and information sources, changing their opinion with some probability. Agents whose peers are more likely to spread misinformation are consequently less trusting than agents whose neighbours are more informed, and therefore change their views with less probability. When echo chambers are strong, weakening them results in there being more interaction between high and low social trust agents, increasing the spread of misinformation.

A platform holds information on the demographics of its users and wants maximise total surplus. The data generates a probability over which of two products a buyer prefers, with different data segmentations being more or less informative. The platform reveals segmentations of the data to two firms, one popular and one niche, preferring to reveal no information than completely revealing the consumer's type for certain.