If immigration fraud is to be reported does the immigrant get deported and what happens to the American who knowingly marries a stranger for money,what is his punishment?

Funny it is much more likely if anything is done at all, ( don't expcet any real rush to investigate) the person taking the money is much more likely to find thierself in legal trouble over the immigrant, who most likely may if ever arrested, be given bail and a date to report, to allow them to merely disappear amount the millions of other illegals.

The citizen of course is tracable by drivers license, social security and can not merely disapper.

But odds are beyond the citizenship not being allowed, little will ever happen. But it can, you never know, maybe some field agent in your arera or something,

Yup, as said above, Immigration (USCIS) doesn't really have the time to deal with this. Just search "immigration fraud" on our site and you'll see the number of people asking this question. They probably receive so many calls from citzens claiming to know of an immigration fraud and they can only realistically investigate so many.

Take a chance and call and maybe they will send someone to investigate, that's about all that can be done.