'Patent violations'

Postman said the technology at issue in the lawsuit, filed in a Washington court on Friday, was created by Interval Research, a company founded by Allen and David Liddle in 1992.

Four patents related to Web search, multimedia, screen pop-ups and database management were allegedly violated.

The list of defendants in the lawsuit included AOL and Internet auction house eBay.

"We believe this suit is completely without merit and we will fight it vigorously," Facebook said in a statement responding to the complaint.

Google also slammed the lawsuit.

"This lawsuit against some of America's most innovative companies reflects an unfortunate trend of people trying to compete in the courtroom instead of the marketplace," a Google spokesman told the AFP news agency.

Microsoft, which Allen founded with Bill Gates in 1975, was not named in the suit.