Some people who are members of Abrahamic religions (Christianity, Islam, Judaism, Mormonism, etc), interpret the (2nd or 3rd Commandment, depending on how you are counting)
"shall not take the lords name in vain" thing to imply that you must not say the word "god" (You will frequently see 'g-d' used by these people). Others see it as a prohibition against using the word "god" irreverently. Others see it as a prohibition against using the word "god" when combined with other "swear words" (this is the "goddamn" case, "damn" being an extremely mild "swear word" that can be found in PG movies). Others still go further and say that the commandment forbids the use of 'minced oaths', such as 'heck' (hell), 'darn' or 'dang' (damn), 'gosh' (god).
For the most part, everybody considers this restriction something that they should only expect of themselves (very similar to how it is unheard of for a Jewish or Muslim person in America to object to somebody else eating pork). Rarely, you encounter somebody who does not have a strong grasp on that concept.