[Roscoe]

There are many situations where omission is fraud

Gee, your Honor, I didn't know the uninspected meat that I bought on the black market was poisonous, so how could I warn that family? Can I go now?

[donh]

Gee, your Honor, I didn't know the uninspected meat that I bought on the black market was poisonous, so how could I warn that family?

uh huh. Do you know what black market means? How is the any different from the previous example? How is it not fraud to fail to disclose the illegal and dangerous nature of this purchase to my customers?

Can I go now?

Sure, as soon as you tell me where we look to determine the constitutionality of a law.