Halachos of Christmas - http://www.bangitout.com/article...
"2. THE TREE SHOULD BE CHOPPED DOWN SPECIFICALLY FOR USE AS A XMAS TREE; IF IT HAD BEEN CUT FOR LUMBER IT IS INVALID. IF THE TREE WAS CUT FOR GENERAL DECORATIVE PURPOSES, BUT NOT SPECIFICALLY AS A XMAS TREE, SOME AUTHORITIES ALLOW IT WHILE OTHERS ARE STRICT. A STOLEN TREE IS NOT VALID FOR THE MITZVAH.9 FORTUNATE IS ONE WHO IS ABLE TO CHOP HIS OWN TREE HIMSELF.10" - Gabe