(Information on interest rates and the PlayStation 3 hack updated in today's Hot Trends article.)

NEW YORK ( TheStreet) -- "Interest rates" is a heavily searched topic today following news that Warren Buffett's Berkshire Hathaway ( BRK.A) sold $1.5 billion of mostly fixed rate debt, signaling that longer-term interest rates may be on the rise.

Bloomberg reported that a unit of Berkshire issued $750 million of 10-year, 4.25% notes and $375 million of 3-year, 1.5% notes.

Some reports interpret Buffett's action as an indication that the U.S. economy is improving.

PlayStation 3 is a trending search topic on the Internet today following reports that Sony's ( SNE) gaming system has been hacked.

According to Sony Insider, a group of German hackers, known as fail0verflow, broke through the PS3 security and gained access to Sony's private software keys.

Sony says that fail0verflow's goal was likely to restore the Linux operating system on PS3 after it was removed from the console last year. The hackers now have access to the PS3 firmware which could allow game files burned onto a Blu-ray disc to work the same as a PS3 retail disc does.

HDTV is a hot search topic today after Vizio announced a new lineup of HDTVs yesterday.

The TVs, ranging from 22 to 71 inches, will support Vizio's 3D feature. An Internet connection will enable users to stream media from online content services such as Netflix ( NFLX), Amazon ( AMZN) and Pandora straight to their TV.

The least expensive E-series come in 32-inch, 42-inch, and 47-inch models. The more expensive M- and XVT-series come in larger sizes and support Bluetooth and feature LED lighting.

Deutsche Bank ( DB) is a popular search topic today after a sell-side analyst at the company upgraded Alcoa ( AA), sending its shares up 5% in trading yesterday.

In a Jan. 3 note, metals and mining analyst Jorge Beristain upped his rating on Alcoa stock to buy from hold based on an improved outlook for the global aluminum market and "a belief that Alcoa has turned the corner from an operational point of view."

He raised his 12-month price target to $22 from $14. Alcoa's share price has risen more than 60% since July, 2010. The stock is up 3.54% to $16.36 in premarket trading.

The chatter on Main Street (a.k.a. Google) is always of interest to investors on Wall Street. Thus, each day, TheStreet compiles the stories that are trending on Google, and highlights the news that could make stocks move.

-- Written by Theresa McCabe in Boston.

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