It was everybody's top homeland security action item after 9/11: consolidate the government's dozen terror watch lists into a single, usable data source. But nearly four years later, it's a project that remains largely undone, Business Week reports.

Computer incompatibilities, slow interagency negotiations, and formidable data-crunching challenges are hindering the coordination of U.S. intelligence data.

While it has made progress, the FBI's Terrorist Screening Center (TSC) says it doesn't know when it will finish consolidating information from a dozen different criminal databases into a master "terrorist watch list" database that can be checked by state and local police, border agents, airport workers, and others...

The TSC has also faced myriad technical difficulties: While the State Dept.'s database had extremely sophisticated code for sorting through complicated foreign names, it's slow. On the other hand, the Justice Dept.'s National Crime Information Center, which is designed to help law-enforcement officials do background checks, operates much faster, but it can't handle complex Russian or Arabic names well...

The present capabilities are a big step from just a few years ago, when no outside agent could get direct access to another intelligence agency's database. And a group that didn't even exist before 2003 needs to start somewhere...

[But] currently, state and local law-enforcement officials use the Justice Dept. database to connect to the TSC list, meaning they still experience the same lookup problems. When a match comes up, the officer must then dial the TSC call center, where an analyst can check the system directly for them. Eventually, the TSC wants to incorporate the biometric data and make it possible for law-enforcement personnel, border officials, and other agencies to query the watch list directly, using its own search engine. Officials at the TSC said they don't have a specific date when they think this could be completed, however.

THERE'S MORE: An "Air France flight currently enroute from Paris to Boston has been ordered to divert and land in Bangor, [Maine] after a routine check of the passenger manifest found a potential match with the no-fly list," NBC News is saying.

"The incredible danger and tremendous inconvenience caused by not clearing names with the terrorist watch list before a flight takes off is completely unacceptable," said Sen. Chuck Schumer, who's always quick to blast out a press release. "We must check the terrorist watch list before airplanes head to the United States."