The New York Times revealed that Pakistani sources gave them the name of the al-Qaeda computer geek, and not the Bush Administration. It's near the bottom of the article, so you might miss it:
The release of Mr. Khan's name - it was made public in The New York Times on Aug. 2, citing Pakistani intelligence sources - drew criticism by some politicians, like Senator Charles E. Schumer, Democrat of New York, who charged that this leak might have compromised the search in Britain and Pakistan for Mr. Khan's Qaeda partners.
The strange part is that the August 2nd didn't mention Pakistani sources, but rather a "senior United States official." In addition, Schumer was whining about the Bush administration rather than making remarks just critical of the compromising the investigation.