In rural America, which was an agrarian society originally, people did not have indoor plumbing and instead used an outhouse. They didn't have toilet paper either, so they had to use whatever was at hand. Corncobs were often used for the purpose. That's how they came to be associated with the rectum.
EDIT: What I said above was related to me by my grandfather, who grew up in a farming community in Illinois in the early 20th century. So it may be folk etymology. Etymonline.com differs somewhat, although I find their explanation bizarre (and note that it is qualified with the word "apparently" — apparently what?
cornhole
synonymous with "do anal intercourse" by 1930s, apparently the reference is to a game played in the farming regions of the Ohio Valley in the U.S. from 19c., in which players take turns throwing a small bag full of feed corn at a raised platform with a hole in it.
FURTHER EDIT:
Etymonline offers no explanation for how "anal intercourse" became associated with an innocuous game. Was there a gay culture on the down-low in farming communities, one that staged mock games of what amounts to bean-bag tossing to cover up homosexual orgies? That seems ridiculous.
Fanboi pre-dates both Avril Lavigne's "Sk8er Boi" song (2002) and Apple's iDevices (iMac, 1998), however usage increased dramatically since the 2007 release of the iPhone, and it is now often used a a put-down when talking about zealous Apple fans.
Usenet
The excellent Technologizer post says "fanboy" originates from the comic collector world, and the earliest references to "fanboi" I can find in Usenet are also from comics groups.
In a 9th October 1996 post to rec.arts.comics.misc, The Comics Journal wrote:
With our renewed dedication to running more reviews, we'll surely end up
dealing more with the mainstream in terms of general reviews. We're also
dedicating a new nearly-every-issue column to the mainstream called "The
Fanboi Politik" by Ray Mescallado. I'm sure many opinions and critical
views will be heard on mainstream works in coming months.
Two days later, PatDOneill replies, showing from the start the term has a somewhat negative flavour:
Oh yeah--that title surely indicates what an even-handed approach it's
going to take.
Migawd--you can't even title a column about mainstream comics (that you're
touting as being written from an appreciative standpoint) without
insulting the people who are fans of such work.
How about if WIZARD retitles its column about alternative and small-press
titles as "The Nihilist, Black-Clad Claptrap"? BTW--ours runs EVERY issue.
Ray Mescallado's signature in a 22nd November 1996 rec.arts.comics.dc.lsh post was:
-- Ray
--
**************************************
* Ray Mescallado * "The politics of failure have
* fan...@avalon.net * failed. We need to make it
* http://www.avalon.net/~fanboi/ * work again." - THE SIMPSONS
**************************************
The post was asking the Legion of Super-Heroes "fandom" their opinions of the comic for the Comics and Animation Newswire. He wrote a lot about "fanbois".
Urban Dictionary
The earliest Urban Dictionary definitions aren't until 2003, but both clearly have negative meanings:
fanboi
Someone who is hopelessly devoted to something and
will like anything associated with their particular thing.
That damn fanboi only likes that game cause Capcom made it.
The only reason he bought that car is cause he is a Japanese fanboi.
Source: Jevin, Jun 19, 2003
fanboi
Alternate of fanboy.
You must be either retarded or a fanboi.
Source: loser, Apr 7, 2003
iPhone fanbois
More recently, both fanboy and fanboi are used to describe zealous fans of technology and products, in addition to comics, games and films. The use of fanboi is especially used to describe ardent fans of Apple products, and in particular appears to have increased dramatically around the 9th January 2007 announcement and 29th June 2007 release of the iPhone.
The Register is an IT news site particularly fond of iconoclastic slang. A quick tally of their 116 articles including the word fanboi show 111 are in the context of Apple/iPhone/iPad/iMac/Mac/MacBook. (The others are Java (x2), Rackspace, AWS, and e-voting.) The earliest was published in an article titled "iPhones, iPhones and more iPhones" on 13th July 2007, and is a round up of comments following the recent US release:
I _heart_ Apple
..........Insert sycophantic drivel here..........
Apple Fanboi
Google's Insights for Search backs this trend up. The main peak begins in November 2006, soon before the iPhone's official January 2007 announcement, as hype around Apple's rumoured iPod-mobile phone was "reaching fever-pitch".
Best Answer
Munge was around in Yorkshire before 1950s, and can be seen here recorded in 1876:
Munge
to chew eagerly, or munch.
A person is said to munge, too, who murmurs surlily in an inarticulate manner.
The second usage, the surly inarticulate murmur, seems to fit your imperfectly transformed data or mumble more than the chewing does.