In a move that could signal its intention to go to court against two Internet giants, the U.S. Justice Department has hired the former head of its antitrust division to look at a revenue-sharing deal between Google and Yahoo Inc.

As dissident shareholder Carl Icahn warned that Yahoo! is “moving toward a precipice” and “it is time for a change,” Microsoft said today it could renew its effort to buy Yahoo! The catch: First Yahoo! shareholders must vote in a new slate of directors at their Aug. 1 meeting.

Wouldn’t you love to know what you’d earn if you worked for your employer’s biggest competitor?

We wish we had said it first. The Wall Street Journal’s Deal Journal made the observation Monday that investor Carl Icahn has adopted the Securities and Exchange Commission as his personal blog.

Microsoft has brought in a Washington lobbying firm, Bryan Cave Strategies, to help in its drive to buy Yahoo.

Three of the biggest companies in the music industry will be providing content for web-newcomer PluggedIn, which offers high-definition music videos and concerts to be streamed online for free.

Microsoft’s bid to acquire Yahoo has put a harsh spotlight, perhaps too late, on the company’s board.

Kara Swisher, writing on All Things Digital this morning, predicts that the directors’ response to the unsolicited buyout attempt may simply be inertia.

Being pursued by Microsoft hasn’t deterred Yahoo from its own pursuits of smaller fry.

Yahoo announced yesterday that it had paid $160 million for Maven Networks, a firm that sells video-management systems for online advertising. Maven’s customers include such major media outfits as Gannett, Scripps and Fox News.

Can Google maintain the company motto - “Don’t be evil” - while building a powerful lobbying machine?

That’s just one of the challenges facing the internet giant. Another is Microsoft, a competitor not only on the web, but in the courts and the halls of Congress.

Such a deal has long been speculated about because of Yahoo’s sagging prospects. This morning Microsoft made it a reality by offering $44.6 billion ($31 a share) for Yahoo! That’s more than a 60 percent premium over Yahoo’s closing price Thursday.