Sedo sent out a security email today with the following message :
We have been informed that due to a security problem at one of our competitors a list of their customer data including plaintext passwords is currently circulating on the web including relevant hacker forums.
Our Security and Compliance Team has found several of our own customers matching the publicly available list. Due to the seriousness of this matter combined with the possibility that you might be using the same login data/password at more than one parking company, we strongly suggest you to change your password at Sedo.
Sedo uses cryptographically unbreakable ciphertext for password checks and does not store your password in plaintext. This, and a variety of other security measures, ensures that your Sedo account is always safe from third parties.
We generally recommend to always use different login IDs for different sites and never hand out login IDs to any third party.
Should you have any further questions or needs, your dedicated account manager is looking forward to help.
Kind regards,
Your Sedo Security and Compliance Team
Although not named, apparently they are referring to Name Drive, which has had a lot of accounts hacked recently. Because of the number of parking companies available to domainers, Sedo were concerned that NameDrive account holders who have their account hacked will have the same email and password login as Sedo.
If you do have several accounts at domain registars and parking websites, it’s worth using different passwords for each one incase something like this happens 
Update February 6th
I receiived this email from NameDrive today.
Hello,
This is a mail to inform you that a minimal number of NameDrive accounts
were the targets of a security breach recently.
This affected less than 1% of our database.While we do not believe that your account has been affected and we have
no indication of unauthorized access, we are informing you as a
precaution that you should change your login passwords to any other
online programs for which you use the same password as you do to log
into NameDrive.com.Your NameDrive password has already been changed automatically for you.
If you haven’t already done so, you can retrieve your new password by
logging into your account on the NameDrive homepage.While we have always had strict security measures in place, we have
taken yet further measures to enhance our security measures with
immediate effect.If you have any questions, please feel free to contact us at
info@namedrive.com.Your NameDrive team
