Should someone piss you off to the point of really wanting them gone, DO NOT take the expensive option of blocking an IP address. It’s foolish and an utter waste of money. Yes, I’ve heard of people doing that here on WP.
Blocking an IP address is a waste of time and money! An IP address is changeable. Switching a motum off and back on provides a new IP address. Take a laptop or phone to Starbucks or anywhere else with an internet connection. BAM! A new IP address. For those unsavvy enough to know this, websites exist which you can log into which change your IP address every few minutes making it difficult to trace you. Yes, I have techy geek friends. I’ve known this tidbit for years! Switching internet providers gives you a new IP address. Hell, you can call your internet provider and request a change of IP address.
As with most things, do some research before taking an action which will cost you a couple hundred dollars, unless you have enough money to spend foolishly.