Francois posted on the homepage of Domaining.com the following:

BREACH SECURITY ALERT Domaining.com has been apparently compromised, login has been closed. We were not storing any CC data but change your password in other services if you were using the same. More info later, sorry.

Hopefully Francois will get to the bottom of this and provide an update today.

UPDATE: I received an email about an hour ago from Francois

I am sorry to inform you that the server hosting the database of Domaining.com has been compromised and hackers succeed to access user data.
We do not charge advertisers by credit card so none has been stolen.

What is important and urgent is to change your password on other services if you are using the same or similar password on your domaining.com account.
On our side we have already closed the sign up and login pages to prevent unauthorized access to your Domaining.com account.
We should not open it again without previously resetting all passwords, ensuring that the security hole has been closed, and the site is audited by security experts so it does not happen again.
When done we will contact you again to reset your password for recover access to your account or simply close it.

I apologize for the inconvenience,

Francois
Domaining.com