According to Cert-FI (Finnish national reporting point for computer security incidents and information security threats), LinkedIn was hacked and nearly 6.5 million accounts (of their reported 150 million, so less than 10%) were compromised.
Emails, passwords and other pertinent information is now in the hands of someone associated with a Russian hacking website (that is now offline, but the damage is done.)
It's true that the information that was taken was encrypted, but if you have the right hacking knowledge, those encryptions are only a temporary measure until the true information can be seen. ZDNet has reported that 300,000 weak passwords have already been discovered.
Photo Credit: ZDNet
What's considered a weak password? If you use lower-cased letters only, particularly 6 or less characters in length, your password is weak and you should look into changing it asap.
At this point though, even if you used both upper and lower-cased letters, numbers and even symbols, you should go to LinkedIn and change your password now. 'Cause you could be part of the lucky 6.5 million users that has had their information hacked.
It's also recommended that if you use the same password for your email account associated with your LinkedIn account that you go and change that as well. Particularly if you're using a general public inbox, such as Hotmail, or Yahoo!. It will be so easy for these individuals to go to hotmail.com or gmail.com to check and see if the password they have is a skeleton key to your entire online existence. (EDIT, trust me when I say it's no strip off their back to check PayPal too if you happen to have a one-password-fits-all!)
Are you worried now?
The best and only way to keep yourself safe from this potential threat is to go change your passwords.
I'm not sure if I can emphasize that enough.
The really interesting aspect of this ordeal, at least at the time that I'm writing this, is that LinkedIn as kept hush-hush about it.
What are you still doing here? Go!