An example of using IPs to combat abuse is Wordfence. It's a WordPress plugin which blocks traffic from known abusive IPs. A quick glimpse at the "live traffic" for one of my websites reveals several IPs within the last hour that have attempted to access the site which were blocked.
A site I was repairing after a hack fortunately had server logs which included IP data. That IP allowed me to identify the specific exploit used.
So, there are definitely uses for IP data in security terms.