Brunei, a Muslim nation in Southeast Asia, has banned Christmas displays.

Referring to “Christmas decorations such as Santa Claus figures, Christmas trees, banners displaying Christmas greetings, and sales personnel dressed like Santa Claus,” Brunei’s ministry of religious ministry stated that “Muslims should be careful not to follow celebrations such as these that are not in any way related to Islam.”

“Muslims are prohibited from imitating the customs and practices of other religions that are related to matters of aqidah (faith),” the decree continued. “Meanwhile, believers of other religions that live under the rule of an Islamic country — according to Islam — may practice their religion or celebrate their religious festivities among their community, with the condition that the celebrations are not disclosed or displayed publicly to Muslims.”

“The act of publicly displaying festivities of religions other than Islam can be seen as propagation of religions other than Islam, and it can amount to an offence,” the ministry cautioned.

http://www.catholicculture.org/news/headlines/index.cfm?storyid=23725

Personally I think that if they think Santa Claus is part of the Christian religion then they don't know much about Christianity.