LEGAL SKIRMISH: Yahoo is expanding its allegations of intellectual property theft against Facebook. In court papers filed Friday, Yahoo Inc. says Facebook's online social network is infringing on 12 of its Internet patents. That's up from the 10 alleged violations that Yahoo cited when it initiated the lawsuit March 12.
GETTING NASTIER: Yahoo denied allegations that it's also infringing on Facebook's patents and accused its rival of engaging in shady conduct. Facebook said it's perplexed by Yahoo's "erratic actions."
MORE DRAMA LOOMS: The acrimony is spilling out as Facebook prepares to raise $5 billion in a highly anticipated initial public offering of stock.