Filtering Software People who believe that information can change the way a person thinks and believes often support the use of filtering software. 9 The increasing amount of information available on the Internet and the unlimited topics it covers also lead proponents to encourage the use of filtering software. The growth rate of information is so quick that filtering software offers one strategy to providing a supportive environment for teaching and learning. Filtering software is also less expensive than evaluating or previewing individual sites. Unfortunately, filtering software is not always effective. 10 The rapid growth that may encourage filtering software means they must be updated often to keep pace with the Internet. Filters can block desirable and they do not take into account the varying ages, levels of maturity, and individual needs of users. Keywords used to ban sites are often derived subjectively and most filtering services do not publish their lists. 11 Schools that use filtering software without knowing which sites are being blocked and why may unintentionally censor materials that are constitutionally protected. Schools or filtering software developers that claim they prevent students from viewing objectionable material may also open themselves up to litigation if the software is not completely effective. 12 Remember, too, that the Children's Internet Protection Act (CIPA) requires that all schools receiving E-rate funding in the fourth round of allocations must install a technology-based solution to block material listed in the act. Filtering software is one technology-based solution to help schools comply with the CIPA.