They probably have more data on minorities than on insecurities. Some ad networks can tell your gender and ethnicity with reasonable accuracy (especially in the

They probably have more data on minorities than on insecurities. Some ad networks can tell your gender and ethnicity with reasonable accuracy (especially in the aggregate). Stack Overflow might be affiliated to one of those, or use data mining algorithms similar to what they use. They also run polls among their users, I believe. It's easier to ask about gender/race in a poll than about unspecified insecurities.