Facebook shares have lost nearly half their value since a highly-touted public offering in May, but it's still not a bargain for some.

Facebook in the past week dropped below $20 a share for the first time since its $38 offering price in May. On Friday, the stock rebounded five percent to $21.09 but remains down a hefty 44.5 percent.

The professional social media group LinkedIn reported better-than-expected results Thursday, giving some relief to a sector battered by disappointments from Facebook and others.

LinkedIn reported a profit of $2.8 million on revenues of $228 million in the second quarter.

Facebook's latest figures showing growth in global users also suggest as many as 83 million may come from dubious sources -- duplicate accounts, pages for pets and those designed to send spam.

Facebook members grew to 955 million at the end of the second quarter, but some 8.7 percent may be dodgy, the company said in its quarterly filing with the U.S. Securities and Exchange Commission.

South Korea's Samsung Electronics said Friday it would unveil a new mobile device this month, just weeks before the likely debut of the iPhone 5 from arch-rival Apple.

A spokesman for Samsung, the world's largest smartphone maker, declined to give details of the device to be shown in Berlin on August 29, two days before the opening of Europe's largest consumer electronics show IFA.

European researchers said Thursday they had developed the world's first real-sized, five-fingered robotic hand able to grasp and manipulate objects with human-like dexterity.

Getting robots to maneuver objects with precision has posed many problems for engineers in their quest to build humanoid machines to serve as domestic aides, emergency rescuers or factory workers.

Rovio, the Finnish makers of the world's most-downloaded mobile app "Angry Birds", will seek a stock market listing by the end of 2013, chief financial officer Mikko Setala said in an interview published Thursday.

"We have prepared a stock market entry for 2013. But the shareholders have not decided when or whether it would even happen," Setala told Swedish economic newspaper Dagens Industrii.

Mobile phone and Internet services have been cut in Aleppo, Syria's second city, where a crucial battle is taking place between rebels and the army, the Syrian Observatory for Human Rights said on Thursday.

"Mobile telecommunications services and Internet have been cut off in the city of Aleppo since last night," it said.

Twitter on Wednesday launched a new political index aimed at gauging the 2012 U.S. presidential race by analyzing daily tweets.

In the first release, the index gave U.S. President Barack Obama a score of 34 -- down four points from the previous day -- to 25 for Republican rival Mitt Romney, who was up two points.

A U.S. regulator Wednesday proposed tougher standards to protect privacy and collection of data of children using the Internet.

The Federal Trade Commission unveiled a proposal to expand the scope of privacy rule not just to website operators, but to third-party applications and "plug-ins" which may be on social networks or on mobile phones.

Google and Apple have both removed an application from their app stores used by Hizbullah to stream its al-Manar satellite network, media reports said.

The app which was on display on July 25 was removed from the iTune stores four days later and Google followed two days after removing the app from Google Play.