Writing the Name of God
http://www.jewfaq.org/name.htm
" Jews do not casually write any Name of God. This practice does not come from the commandment not to take the Lord's Name in vain, as many suppose. In Jewish thought, that commandment refers solely to oath-taking, and is a prohibition against SWEARING by God's Name falsely or frivolously (the word normally translated as "in vain" literally means "for falsehood").
Judaism does not prohibit writing the Name of God per se; it prohibits only erasing or defacing a Name of God. However, observant Jews avoid writing any Name of God casually because of the risk that the written Name might later be defaced, obliterated or destroyed accidentally or by one who does not know better.
The commandment not to erase or deface the name of God comes from Deut. 12:3. In that passage, the people are commanded that when they take over the promised land, they should destroy all things related to the idolatrous religions of that region, and should utterly destroy the names of the local deities. Immediately afterwards, we are commanded not to do the same to our God. "
Notice the SWEARING in G-d's name is not cussing but is in relationship to using it to validate a falsehood.
When there is something said or written in the name of G-d that is not true, it'll prove itself to be false, this is taking the Lord's name in vain.