These conditions also applied to a small subset of grants authorized through the Library Services and Technology Act (LSTA).

As of 2007, approximately one-third of libraries had chosen to forego federal E-Rate and certain types of LSTA funds so they would not be required to institute filtering.

The following content must be filtered or blocked: Some of the terms mentioned in this act, such as "inappropriate matter" and what is "harmful to minors", are explained in the law.

§ 254(h)(1)(B).The CIPA defines "harmful to minors" as:[3] Any picture, image, graphic image file, or other visual depiction that – (i) taken as a whole and with respect to minors, appeals to a prurient interest in nudity, sex, or excretion; (ii) depicts, describes, or represents, in a patently offensive way with respect to what is suitable for minors, an actual or simulated sexual act or sexual contact, actual or simulated normal or perverted sexual acts, or a lewd exhibition of the genitals; and (iii) taken as a whole, lacks serious literary, artistic, political, or scientific value as to minors.As mentioned above, there is an exception for "bona fide research".

Justice Rehnquist stated "[a]ssuming that such erroneous blocking presents constitutional difficulties, any such concerns are dispelled by the ease with which patrons may have the filtering software disabled.

The U.S. Federal Communications Commission (FCC) subsequently instructed libraries complying with CIPA to implement a procedure for unblocking the filter upon request by an adult.

In a 200-page decision, the judges wrote that "in view of the severe limitations of filtering technology and the existence of these less restrictive alternatives [including making filtering software optional or supervising users directly], we conclude that it is not possible for a public library to comply with CIPA without blocking a very substantial amount of constitutionally protected speech, in violation of the First Amendment".

Upon appeal to the U.S. Supreme Court, however, the law was upheld as constitutional as a condition imposed on institutions in exchange for government funding.

[7] The argument here is that, the government can offer public funds to help institutions fulfill their roles, as in the case of libraries providing access to information.

The Justices cited Rust v. Sullivan (1991) as precedent to show how the Court has approved using government funds with certain limitations to facilitate a program.

Furthermore, since public libraries traditionally do not include pornographic material in their book collections, the court can reasonably uphold a law that imposes a similar limitation for online texts.