Yahoo has now claimed that Facebook is infringing on 12, rather than ten, of its patents.
“Today’s filing underscores the breadth of Facebook’s violation of Yahoo”s intellectual property,” The Los Angeles Times quoted a Yahoo spokesman, as saying.
Last month Yahoo claimed Facebook had infringed on ten of its patents, including systems and methods for advertising on the web.
Facebook, however, counter sued the Internet firm, claiming Yahoo violated its patents covering photo tagging, advertising and online recommendations.
According to the report, Yahoo has now denied the claims and accused Facebook of engaging in unfair tactics.
It said Facebook violated an agreement between the two companies to notify each other of possible patent infringements before going to court.
Meanwhile a Facebook spokesman said that they are ‘perplexed by Yahoo”s erratic actions.’
“We disagree with these latest claims and we will continue to defend ourselves vigorously,” the spokesman added.