LinkedIn has refreshed its mobile presence today with the launch of redesigned apps for iPhone and Android, plus a brand new HTML5 mobile website.  The iPhone and Android apps have been reorganized around four core areas. Updates from your network and inbox, your profile, and information about your network are all accessible via the new slick, highly visual interface.

The Groups feature is also now available for the first time in the mobile app, with access to the list of groups you’re a member of, along with discussions and the ability to start new discussions or engage with existing ones.  The company says access to Groups was the most-requested feature for a mobile update.

LinkedIn is increasing at a rate of 400% year-on-year, and the company has expanded its mobile development team in response.  As such, the new apps provide a newly optimized experience for the fastest-growing part of the service, and mobile is a definite focus for LinkedIn, and the social networking industry as a whole.

LinkedIn’s new mobile apps also focus on speed. The company says that its mobile apps are up to 10 times faster.  This should make searching for content or checking out your friends’ updates less painful, depending on the feature you’re accessing.  The apps have also been designed to highlight the most used feature–the update stream. LinkedIn, which has more than 120 million members, also redesigned its entire mobile platform to make the experience seamless no matter what mobile browser is used, lending its support to the HTML5 movement.

But all is not well for LinkedIn, as it had to quickly respond to some negative feedback from its site users this week.  It was reported that LinkedIn is sharing its user’s private information with their business partners, a move that got Facebook in trouble a couple years ago.  Over 100 million users are upset that the company has taken the Facebook approach in regards to online privacy with a recent change to the privacy policy. The social network has automatically opted in its users into the social advertising program without informing them of the change beyond a blog post.

When a LinkedIn user views a third-party advertisement on the social network, they will see user profile pictures and names of connections, and if that connection has recommended or followed a brand.  Anytime a user follows a brand, they unwittingly become a cheerleader for the company or organization if it advertises through LinkedIn. But all these reports are explained and were clarified by LinkedIn on a blog post the day after, stating:

“We never share personal information with third-party advertisers. That was true prior to the launch of the social ads test, and remains true today. The only information that is used in social ads is information that is already publicly available and viewable by anyone in your network.

“Most importantly, we made it easy for our members to opt-out of inclusion from all social ads with one click. On each member’s Accounts and Settings page, the first option under Privacy Controls (under the “Account” tab) is “Manage Social Advertising.”