First phishers, now hackers — the Twitter security concern got a little scarier yesterday, with the news that 33 high profile accounts, including those of Britney Spears and Barack Obama, were hacked. Twitter is acting with an alacrity befitting a social media company in responding to the situation, keeping users updated via commendably transparent blog posts.

Mashable points out the challenges this incident creates for Twitter and other social networking sites seeking to engage with users across an expanded social web:

“…this type of attack is clearly going to be a huge PR nightmare as Twitter tries to lure more celebrity users, and may make users think a bit harder before blindly entering their credentials into third-party websites. That goes for services like Facebook Connect and MySpace ID too.“

Michael Arrington at TechCrunch comments:

“Most of us got a good chuckle out of the various messages that were left on the Twitter accounts for Barack Obama, Britney Spears, Bill O’Reilly and others this morning. But one other message came through loud and clear – Twitter is not yet ready for prime time, even though users continue to flock to the service.“

ReadWriteWeb’s Marshall Kirkpatrick voices what the guys at Twitter at HQ are no doubt thinking as well:

“This can’t be good for Twitter. What major brand will be excited to sign up for the service now? Who would pay, even, to be put at such risk?“

Elsewhere on the web:

Jeremiah Owyang points out a possible world first – a corporate blog launched specifically to cover the Wells Fargo-Wachovia merger – along with his thoughts on the type of content that would fit this type of social media property.

Via Steve Rubel, here’s a superlist of social media case studies which should provide an abundance of background information and context for any organisation looking to implement a social media strategy this year.

Marshall Kirkpatrick at ReadWriteWeb got very excited about Music Blog Zeitgeist, a new (very beautiful) music microsite from MP3 blog aggregator Hype Machine which pulls together a slew of different technologies so users can listen to entire albums from the most blogged-about musicians of 2008, for free.