People who are in favor of the bill say that the police and other law enforcers need to be able to go back and look at the records of IP addresses, because these addresses can change over time. So the police need to be able to check the records in order to catch people. occurred. Lamar Smith, the bill's sponsor, said that: ""Some Internet service providers currently retain these [IP] addresses for business purposes. But the period of retention varies widely among providers, from a few days to a few months. The lack of uniform data retention impedes the investigation of Internet crimes." Smith said that the number of child pornography cases grew by 150% a year every year for the past ten years.