My question involves criminal law for the state of: SC

Hi! I overheard my roommate talking to a friend about buying someone's food stamps. I have no idea if the transaction actually occurred, or who the seller is. We share the basics (milk, butter, flour, etc.) and I wanted to know if I'm liable for anything. I'm aware that there are hotlines, but I don't have any substantial evidence to report. My concern is my being charged for not reporting for worse--receiving benefits from said (possible) transaction.

I've asked her about it but she will not give me any details. I've warned her that such is illegal.

Also: if the seller is caught, can my roommate be charged for not reporting and knowingly purchasing something illegal?

I realize that this may sound silly, but I just wanted to make sure. Thanks!