User blog comment:TheDoritoBoyJ/Hi, whats up with this certain rule/@comment-366087-20190912002329

To answer your new, edited question (really, next time, make a new blog. Now replies below look silly answering something different…), sometimes we do. However, ips are often dynamic things. They change over time, being reassigned. While it doesn't happen often, some innocent users have actually inherited ip blocks.

Because of this, ip blocks are advised to be short, not permanent, with about a year the longest.

And all that is not taking into consideration trolls and vandals who *actively* seek to get around blocks. Resetting ips, going to other computers (home, school, work, homes of "friends", etc) and even trying to use VPNs to mask themselves.