This good column by Thomas Bray tells about the new Federal Data Quality Act which says that when studies are relied upon by govt agencies to make policy, the public has a right to see the raw data from which conclusions were drawn.
Now, if only the law applied to studies issued by private pressure groups instead of just govt agencies. E.g., the Anti-Defamation League released a "study" purporting to show that 17% of the American people harbor "strongly anti-Semitic" beliefs. But a writer (who is apparently Jewish) who looked at ADL's raw data, concluded that the study is bogus.
A more serious example of questionable data is the notorious 1998 book The Shape of the River, which claims that affirmative action in college admissions benefits both blacks and whites. The authors of that book have refused to allow their chief critics, Abigail and Stephan Thernstrom, to see the raw data on which the book's conclusions are based. Here are details.