Yesterday Crytek has taken down all of their severs including Crytek.com, Mycryengine.com, Crydev.net and MyCrysis.com. Apparently they have been breached as the pages report a note on 'suspicious activity'.
Thus far Crytek has not released any information about what has happened so it is unclear what user data is vunerable:
THIS SITE IS CURRENTLY OFFLINE
We recently became aware of suspicious activity relating to some of Crytek's websites, and acted quickly to take those websites offline for security reasons.
We thank you for your patience, and expect to have these sites fully operational soon.