You can't use the information directly. It's just a useful guide.

4 seconds sound clip from the Se7en (1995) movie soundboard.

You can hear this line at 01:06:36.093 in the Blu-ray version of the movie.

Quote context

[...]

- Who, stinky man?

- See, for years the FBII's been hooked into the library system, keeping records.

- Mm-hm.

- Assessing fines?

- No, monitoring reading habits.

- Look.

- What?

- Certain books are flagged. Books on, say, nuclear weapons and, well, Mein Kampf. Anyone who checks out a flagged book has his library records fed into the FBI's computers then on.

- Hey, wait, wait, wait, how is this legal?

- Oh, legal, illegal. These terms don't apply.

- You can't use the information directly. It's just a useful guide.

- It might sound silly, but you can't get a library card without an ID and a current phone bill, see?

- So they run a list.

- Precisely.

- If you wanna know who's reading Purgatory and Paradise Lost and Helter Skelter, the FBI's computers will tell us. It could give us a name.

- It could.

- Could get a name of some college kid writing a term paper on 20th-century crime.

- At least you're out of the office. Get a haircut.

[...]