I'm thinking of using the library computer to search for porn.
Have you searched for porn before on the library computers?
No, this is the first time I'm doing it.
Library computers are public property and not for playing out sexual fantasies. Looking for porn at the library is wrong. You will get kicked out for using their computers this way.
What I search is none of the library's business
It is their business because there are also children in that space. If you are watching porn on the Library's computer and a child sees it, you're going to jail for a long time.