To be taken with a large grain of salt.

Judicial Watch is an organization of cranks that makes a career out of filing Freedom of Information requests, filing lawsuits and spreading innuendo. But they don't actually lie. So take it from whence it comes. But:

FBI PROTECTS OSAMA BIN LADEN’S “RIGHT TO PRIVACY” IN DOCUMENT RELEASE
Judicial Watch Investigation Uncovers FBI Documents Concerning Bin Laden Family and Post-9/11 Flights

(Washington, DC) Judicial Watch, the public interest group that fights government corruption, announced today that it has obtained documents through the Freedom of Information Act (“FOIA”) in which the Federal Bureau of Investigation (“FBI”) has invoked privacy right protections on behalf of al Qaeda terror leader Osama bin Laden. In a September 24, 2003 declassified “Secret” FBI report obtained by Judicial Watch, the FBI invoked Exemption 6 under FOIA law on behalf of bin Laden, which permits the government to withhold all information about U.S. persons in “personnel and medical files and similar files” when the disclosure of such information “would constitute a clearly unwarranted invasion of personal privacy.” (5 U.S.C. § 552(b)(6) (2000))

There is also an article about this in Al Jazeera.

The FBI documents that Judicial Watch is talking about can be viewed in pdf format here.