On December 17, Barack Obama signed "Executive Order -- Amending Executive Order 12425" [1] which lifts Ronald Reagan-era limitation on how the international police force INTERPOL can operate inside the U.S. From Andrew McCarthy of National Review (link):

Interpol's property and assets are no longer subject to search and confiscation, and its archives are now considered inviolable. This international police force (whose U.S. headquarters is in the Justice Department in Washington) will be unrestrained by the U.S. Constitution and American law while it operates in the United States and affects both Americans and American interests outside the United States... ...Why would we elevate an international police force above American law? Why would we immunize an international police force from the limitations that constrain the FBI and other American law-enforcement agencies? Why is it suddenly necessary to have, within the Justice Department, a repository for stashing government files which, therefore, will be beyond the ability of Congress, American law-enforcement, the media, and the American people to scrutinize?

See also this, and the possible reasons for this are speculated here:

this immunity and protection - and elevation above the US Constitution - afforded INTERPOL is likely a precursor to the White House subjecting the United States under the jurisdiction of the International Criminal Court (ICC). INTERPOL provides a significant enforcement function for the ICC, just as our FBI provides a significant function for our Department of Justice.

12/30/09 UPDATE: Orin Kerr of the Volokh Conspiracy isn't worried about this:
volokh.com/2009/12/30/
executive-order-12425-and-the-legal-status-of-interpol
However, he also admits that he isn't familiar with these topics; he asks for those more knowledgable to weigh in in comments, and I didn't see anyone like that.

And, Jake Tapper of ABC News throws cold water on this here, quoting a "counterterrorism official from the Bush years" as saying "Conservatives can't have it both ways... You can't be complaining about the hypothetical abdication of US jurisdiction at the same time you're complaining the Obama administration is not being tough enough on national security." Not exactly reassuring, especially if Tapper's unnamed source is Richard Clarke, someone not of high integrity.

1/12/10 UPDATE: The National Rifle Association - more credible than the above on issues like this - says there's nothing to worry about (link). However, Michael Isikoff of Newsweek says the same, offering a standard establishment mocking rebuttal of a Chuck Norris column about this issue (link).

[1] whitehouse.gov/the-press-office/
executive-order-amending-executive-order-12425