Here is the official statement from Eidos Interactive:
"Square Enix can confirm a group of hackers gained access to parts of our Eidosmontreal.com website as well as two of our product sites. We immediately took the sites offline to assess how this had happened and what had been accessed, then took further measures to increase the security of these and all of our websites, before allowing the sites to go live again. Eidosmontreal.com does not hold any credit card information or code data, however there are resumes which are submitted to the website by people interested in jobs at the studio. Regrettably up to 350 of these resumes may have been accessed, and we are in the process of writing to each of the individuals who may have been affected to offer our sincere apologies for this situation. In addition, we have also discovered that up to 25,000 email addresses were obtained as a result of this breach. These email addresses are not linked to any additional personal information. They were site registration email addresses provided to us for users to receive product information updates.
No dissemination or misappropriation of any other personal information has been identified at this point.
We take the security of our websites extremely seriously and employ strict measures, which we test regularly, to guard against this sort of incident."