I’m not sure if this belongs here or in IMHO. Mods, please move if needed.
Over the past few weeks, at least three banned posters have returned as socks. I’m not going to name them, so don’t ask.
My question: Is it that difficult to disguise one’s writing style? I can disguise my signature if needed (not that that has ever come up) but is one’s writing style so ingrained it’s unconscious, and will be a dead giveaway once they attempt to return? Or are there other red flags that pop up?
Depends upon the abilities of the writer. Those with a good eye for the mechanics of style could do a pretty good job of changing their style; but it takes effort.
In the case that we are not discussing here, the poster had a very distinctive style and his presumed sockpuppet seems to have made little or no effort to change it.
I’ve noticed my own posting style tends to have dead giveaways. Either words I use more often, or punctuation I tend to prefer – emdashes for example, “dear, Og!”, and funky-compound-adjective words that are connected by lotsa dashes, and colourful Canadian spelling.
I noticed it mostly while on AIM. My friends use text broken up into single lines. I tend to write longer before hitting send. My AIM style emulates my SDMB style. I’ve also noticed that I can tell be reading my own old posts that there are differences in style between when I’m just fine and dandy and when my biploar disorder is acting up a bit. The differences are subtle, but even I could notice peculiar charactersitics.
I’m sure for someone who isn’t as “close” to my writing, it’s even more distinct. Like an accent.
Most of my posts have at least one typo, but I don’t know if that’s enough to give me away. Like Eats_Crayons, I use emdashes.liberally, along with semicolons. They’d probably find me.
Are socks something of an epidemic here?
Speaking objectively, identifying two different writing styles as being the same depends on who’s doing the writing and who’s doing the investigating. The debate about “Who Wrote Shakespeare” has keep experts going back and forth for centuries. And, of course, how hard the writer is trying to have a changed style will play a role as well.
On the Message Boards, it’s much easier, because it’s not just writing style, but content, favorite topics, political and artistic viewpoints, friends, ego, etc.
We have a lot of jerks who can’t play by the community rules and think it’s fun to sign on as a guest (and thus avoid paying) multiple times. Sometimes we catch them, sometimes we probably don’t, but their month runs out anyway. Such people are, of course, anti-social from our view – unwilling to join our community. As such, they are no better than the drive-by posters who register to post one thing (usually spam, in some form or other) and then vanish forever. Thus, it is to everyone’s benefit (except the spammer, of course) if y’all help us track down these jerks and kick 'em out. They will surely find Message Boards elsewhere that are not attempting to build a community, that will be more to their liking.
This is probably the other big half of the equation. Behaviour is likely the bigger giveaway. There’s also a huge difference in posting styles between newbies who are getting used to the Doper community and those who already know the rhythm. Even if they’re used to message boards and have been lurking. It’s still a little weird when you first start posting somewhere. I sounded like a total dork the first few times I posted on Fark, even though I’m plenty used to message boards in general and have a hefty post count here.
For example, I don’t think I’ve ever posted in Great Debates, but I’m always in the Lost threads. If I was banned and some newbie showed up in the Lost threads, called Licks_Stamps, confidently carrying on a conversation as if I’d been there all along, the second I said “Brrrraaaaiiiins” everyone would know it was really me.
I shall be now be on the lookout for posters called tastes_chalk or gulps_pencils
So, since I’m sensing a theme here, and I bet you really do lick stamps, can I send all of mine to you for such processing? I hate that gummy taste.
(And I owe you one for telling me to “change my pants.” Hrmph.) 
I was thinkin’ maybe Huffs_PaintFumes. All the better to go with a brain damaged persona.
Brrraaaiins
Well, FredSmith being banned and followed by FredSmith01, FredSmith02, Fred Smith03, that was kind of a clue, too.
For real, Dex? In a case like that, wouldn’t it be more of a flaunting, like “Catch me if you can?” I mean, who lives to be banned from message boards? Kind of a sad existence, if you ask me.
We actually had one person who did “lives to be banned from message boards,” though he’s long since given up on the effort. So Dex doesn’t speak in the abstract here, but in…
I’m sure our wise SDMB staff is familiar with the work of Don Foster, writing-style detective extraordinaire, who uses a close examination of particulars of style to determine (and to match) authorships. (His AUTHOR UNKNOWN is discussed here http://www.amazon.com/exec/obidos/ASIN/0805068120/002-7806725-2343224?_encoding=UTF8&coliid=&colid= and elsewhere on the Net.) A fascinating field, particularly for those interested in matching up the styles of “two” writers whose true identities are unknown. I’ve used some of his techniques in tracing amateurs ( students who plagiarize) and I’m sure the techniques would be helpful in determining whether a new poster is a sock puppet or not.
Is that how the author of Primary Colors was discovered, through writing styles?
I’m pretty sure it was through handwriting analysis. I’ll have to see if I can find a cite
Well, looks like it was both - style narrowed it down to Klein, handwriting analysis proved it.
Not as Foster tells it. It was purely through writing style that he outed Klein as “Anonymous.” He tells it in AUTHOR UNKNOWN, though it’s been a while since I read it, and returned it to the library.
Once one of the recent offenders had been banned, but before I knew it was for a hosiery offence I thought to myself “I wonder if that poster was a sock?” and imediately guessed correctly just whose sock it was. It wasn’t the obvious one, nor was it a poster I had any relationship with, nor indeed any particular interest, so I was intrigued that I guessed so quickly. It seemed to imply a that a lot of unconcious processing and categorising of posting styles is going on in my brain.
“hosiery offence”
For some reason, that made me snerk right out loud. 
I’m not trying to be snotty about this, but that statement strikes me as “nah_nah_nah I know something nobody else does.” 
Ted “the Polish Bomber” was turned in by his brother, who recognized his writing style, subject matter, etc.