Bills, and sections of bills, are studied in committee, of course. And, depending on how many of the elected ones turn up for the committee meeting, usually four or five Members of Congress know what was originally in the bill. But, the bill presented for approval by the chamber as a whole is often quite different from the one that passed a committee. Congressional staff has been doing that for many years. Often no one, not even the supposed author of the bill, will read it before the vote.
Prosecutors do, however.
This month was the end of session. Senate records show that no person in the Senate had yet read the bill, but it passed. A dozen or so oppressive add-ons were sneaked in. They all passed along with the original bill. We citizens will not know exactly what all was added for a while.