Ah, I'm now on a static IP because I was having problems with their dynamic ones recently and they suggested that I switch. I wonder if the config file for that is considered a log.
(I don't work for them, but I have worked at small and large ISPs.)
The law enforcement agency will ask for a subpoena that will ask for "all records, logs, files, documents... relating to or describing the subscriber(s) using the IP address $dottedquad at or around $date(s)". The config file that keeps your static IP associated with a MAC address or whatever will certainly be turned over.