San Diego (CA) - Internet users running Websense, a filtering service that blocks out potentially harmful sites, found themselves unable to use Yahoo earlier this week.  An internal mistake caused the online service company to get tagged as a malicious site.

Beginning during the day Tuesday, and all of Wednesday, it was impossible for Yahoo to make its way through the automatic filtering.  Because Websense is largely used by companies, most affected users were not able to disable the software.

"The details are still under investigation but some IP addresses associated with the Yahoo.com site were classified incorrectly," said a representative for Websense.

The company's IT team has recently fixed the problem, and says all sites with Yahoo extensions are now unblocked.