As I remember for SARS-1 it was bats via palm civets sold in wet markets.

It would be interesting to see an updating Bayesian model played out over 18 months of investigation into SARS-COV-19 natural origin with no result so far. Absence of evidence is not proof of non-natural origins, but it does shift one's priors.

Thanks. I guess beyond the stereotypes there's no actual conspiracy theorists. Just people reasoning imperfectly with imperfect data.