I think it's a typo in a book I'm reading, but let me ask:
"Obviously it is not be overused" should be "Obviously it is not to be overused"?
1. Obviously, it is not be overused. It should be to be overused.
2. Obviously, it is not to be overused.
The first example is correct is the writer's intention is to say the words be overused (note the italics) are for some reason or another used incorrectly.