The Obama administration has directed the military to not allow personnel to say “Christmas”, in spite of the holiday’s status as a federally-recognized holiday.
The reason given by armed forces officials is that not everyone celebrates Christmas and that out of respect for them, military members should refer to Christmas celebrations simply as “holiday”-themed festivities.
This prohibition comes in the context of a wider push for political correctness in society in general and the military in particular, as evidenced by the recent reprimanding of Navy Chaplain Wes Modder for simply discussing religion, as chaplains are wont to do, with military personnel.
See how servicemen have reacted to not being allowed to say Christmas at the link below:

Sorry but soldiers do have the freedom of speech like the rest of us!! Outrageous!!!!
ILLEGAL order
F**k off Obama this is a joke just like u are
Merry Christmas Barack Obama! !!!!!!!!!!!!!!!!!!
Hope everyone has a Merry CHRISTmas..
This is an UNLAWFUL order that is directly violates the first amendment. Oh yeah Obama doesn’t read the constitution…
People it a lie don’t believe anything on Facebook
It made uo
Why does people believe everything they read it a lie people
It’s not true…
http://www.snopes.com/obama-military-christmas-ban/