Everything that we say or do, we speak or act into creation. From that point forward we are responsible for the ways in which our creation changes reality. However, in that regard we are perpetually in the path of the creations of others. One should never think, "what will happen when this gets back to me," but "how will this affect those in the path of my creation."
It is like a boomerang, do not aim at others, and think first of who may be in its path before you throw.