If authorities find access logs or some other linking between an IP address and the access of illegal materials online, in order to trace down who the owner of the IP address is any IP assignment logs that links address to customer would have to still exist before an ISP deletes them. For example, if the logs they find show a viewing from an IP several years ago, there’s a chance the suspect switched providers a long time ago and possibly no longer possesses the computer he/she used (as well as possibly destroying his/her hard drive) and the ISP would have no use for those IP assignment logs and deletes them, so that if the authorities try and subpoena the ISP for them they might come up empty (this would be well beyond the reasonable data retention period before the authorities would actually try and subpoena).
Isn’t it true that any logs linking a customer to an IP address will eventually be deleted/destroyed by the ISP (typically because holding on to data that isn’t relevant to them is a pointless expense) making it so authorities who use IP addresses to link a customer to a crime only have a limited amount of time to pursue a prosecution? For the sake of the argument, assume the access log would be the only evidence authorities are able to get.
When companies talk about how long they hold on to data in their privacy policy, are IP assignment logs part of that?