While the author wasn't able to find more than a few logs, it seems that the person has gained a large level of (in)famy in all things web, being refered to the greatest flamer ever, et cetera. Also, perhaps as a joke and the background of his nick, it's said that he gets his "temperament" from, ever-so-typical of the finns, drinking large amounts of coffee.
Some state that he used to be an owner of a large IRC Network, a game site and a forum, that quite simply snapped. Also, perhaps one of the original developers of IRC.
Coffee-Addict also refers to someone who stays on nearly 24/7, presumedly because of large use of coffee.
<TunaFM> and here our next contestant for the title of Coffee-Addict, Leprechaun!
(Lemur) You've been awake for how long? Coffeeaddict or something maybe?
person 2) Yo shes a coffee addict/junkie!