In case you had not heard, Linkedin (the business related social network) has been hacked and some 6.5 million passwords have been stolen. Well actually, the password hash has been stolen and the bad guys still need to try to crack those passwords.
ZDnet has a quick explanation here if you want to know more, but the reality of the issue is..
1... if you have a Linkedin account you should CHANGE YOUR PASSWORD immediately. ( to a strong password 8+ characters, unique, with upper and lower case and alpha numeric and unique characters)
2... if you had a weak password it may have been cracked by now
3...if you used that password ANYWHERE ELSE on the internet, you should change it there as well.
If you are curious if your password hash was on that was stolen, you can go here http://leakedin.org/ and check. Note... I can not verify the legitimacy of this site, however, I do trust Steve Gibson who does the Security Now podcast for This Week in Tech and he believes the site is a legitimate way to determine if yours was part of the stolen hashes. If you go here and fast forward to 30:05 to hear the story about linkedin. (or 33:30 specifically about the leakedin.org site)
I followed their advice and changed my password on Linkedin FIRST and then went to the site to see if mine had been leaked.
In any case... change your Linkedin password and if you are still using simple, insecure passwords... change those now as it is only a matter of time before you will be hacked.