Crytek have temporarily taken four of their websites offline following "suspicious activity". You can no longer access Crytek.com, Mycryengine.com, Crydev.net or MyCrysis.com - basically, pretty much anything with the word 'cry' in it (er, except crysis.com) is gone until the holes are patched up. If you have an account with the latter two, you'll be asked to change your password when they return, and if you use the same password anywhere else, Crytek are advising you to change it there as well.
Thankfully, Crysis.com, GFACE.com and Warface.com are all safe - as is Ryse.com, mainly because the latter is something to do with 'energy healing', and is no relation at all to the QTE-fest Crytek are developing for the Xbox One. Crytek are "working on getting all websites fully operational again as soon as possible".