Last week, LinkedIn, a site where professionals network with each other, sent some users this less-than-urgent email:

However, at the same time, LinkedIn’s chief technology officer posted this more dire warning on the company’s official blog:
*MOUSE PRINT:
In 2012, LinkedIn was the victim of an unauthorized access and disclosure of some members’ passwords. At the time, our immediate response included a mandatory password reset for all accounts we believed were compromised as a result of the unauthorized disclosure. Additionally, we advised all members of LinkedIn to change their passwords as a matter of best practice.
Yesterday, we became aware of an additional set of data that had just been released that claims to be email and hashed password combinations of more than 100 million LinkedIn members from that same theft in 2012. We are taking immediate steps to invalidate the passwords of the accounts impacted, and we will contact those members to reset their passwords. We have no indication that this is as a result of a new security breach.
…
UPDATE: May 18, 5:30 p.m. PT
We’re moving swiftly to address the release of additional data from a 2012 breach, specifically:
We have begun to invalidate passwords for all accounts created prior to the 2012 breach​ that haven’t update​d​ their password since that breach. We will be letting individual members know​ ​if they need to reset their password.
So he’s saying that maybe over 100 million emails addresses and passwords (actually 117 million according to news reports) were stolen previously and are now for sale, and not just the 6.5 million originally believed.
It seems that their casual email to members seriously underplays the seriousness of the situation. And as we’ve said before, the worst mouse print is the disclosure that is not made.
UPDATE MAY 25:
LinkedIn just sent a “Notice of Data Breach” to registrants outlining in more detail what happened. (They must have read Mouse Print* this week.



