I was feeling a little torn on what to write about today, because it seemed like an appropriate time to discuss the Tarantino/Lucas Index...but on reading some discussion about the Don Imus controversy, I felt like it was a better time to discuss Finn's Limit.
Finn's Limit, which is named after the amazing and spectacular Finn Clark (who is hopefully honored and not irritated by my naming this after him) is the point at which any message-board discussion between two or more people with fundamentally opposing points of view ceases to be an exchange of information and opinions and transforms into people repeating themselves in an effort to get in the last word. Finn himself set Finn's Limit at about three posts per person; I named it after him because he never bothered posting more than three times on a topic, figuring if he hadn't convinced the other person by then, he never would.
Internet debates beyond Finn's Limit have interesting sets of behaviors you can almost invariably find if you look for them; for example, a post-Finn's Limit tactic is the Judo Last Word, wherein the person posts that this will be their last post on the subject and that the other person can, if they want, have the last word, because they're no longer worthy of attention. Of course, as soon as the other party responds, they become worthy of attention again.
One question that has yet to be settled is whether or not multiple parties grouped into two camps increases or decreases Finn's Limit; it does, however, undeniably increase the length of discussion beyond Finn's Limit. This "zombie thread" effect occurs when a subset of posters on either side continues the discussion beyond the interest levels of the majority of the posters. People drop out of the discussion, frustrated at their inability to convey their point of view; however, since the discussion continues, they can find themselves dropping back in when a particularly interesting or infuriating point comes up. This, in turn, prompts other people to jump back in, and the discussion continues.
Some long-standing discussion topics permanently pass Finn's Limit; that is to say, even if they die down completely, the next time they're brought up, the exchange will begin beyond Finn's Limit and stay there. A partial list of these topics would have to include "UNIT Dating", "Lives Before Hartnell", and "It's Season Twenty-Seven, Not Season One." (If you're not a Doctor Who fan, you might not understand these references. Count your blessings. If you are a Doctor Who fan, please don't fill the comments section with your personal views on these topics. They're past Finn's Limit.)
Finally, I'll point out the useful aspect of Finn's Limit (because this isn't just a snarky post about message-board forums.) I use Finn's Limit myself, in everyday life--when I've posted three times about something, and I see that the same person who's responded to my post the first three times is disagreeing with it again...I just let it go there. Life's too short to keep talking just to get in the last word. It's frustrating for a minute or two...and then I forget about it.