Any behavior that a society believes directly or potentially injurious to others may be legitimately outlawed. Of course, a society is responsible to enact only laws that it intends to enforce and can enforce. Any behavior, private or public, victimless or not, which a society declares criminal and then does not enforce undermines the rule of law, promoting a lawless society.
So the crucial element in lawmaking is not whether an act is private or whether there is a direct victim who complains, but whether that society judges the behavior to be potentially or actually injurious to others and whether society has the will to enforce the legislation.
Robertson McQuilkin, An Introduction to Biblical Ethics, pg.354