News bites: Yahoo exploring deal with Tumblr

Apple is aggressively fighting back against a Justice Department antitrust lawsuit that accuses it of waging an e-book price-fixing scheme, The New York Times reports.

Yahoo is looking to strike a deal with blogger service Tumblr, AllThingsD says.

The CIA is trying come up with the right guidelines for its agents' use of social media, according to The Wall Street Journal.