No, I know there have been many banned posters who repeatedly come back (briefly) under a series of new names, each one banned by the Admins. All that proves is the banned poster’s bull-headedness.
I find it more interesting that a poster can get himself banned, sweet talk the mods into letting him come back, then gets himself banned again! 
I’d have to assume that it’d take quite a bit more guile to talk his way back onto the board a third time.
Eric
I assume it is because the mods are too busy to check each and every new poster, specially in a board this popular. In my personal experience the quickest way to discover sock puppets are their attitudes.
Someone who has been “politely” invited to bug off and insist in coming back uninvited surely has some issues, so they will make sure that they continue sharing their “words of wisdom” with the rest of the world. If someone who is, for example, a rabid racist with a belief that there is a name any conspiracy, he/she will be quickly spotted doing the same thing that got her/him banned in first place.
Darn! I am too slow. My post was in response to SmileyDeath.
A few reasons spring to mind:
As has been mentioned before, the mods have lots of other things they have to keep up on without adding the IP checking of every post (I’ve posted from several different IP addresses in the past 2.5 years, and I can think of several other people who have as well) of every poster regardless of post count.
Sometimes IP address isn’t indicative of someone being a returning troll. Let’s say Joe Dix goes to State Tech Community College (a school that actually exists. Exit for it on, IIRC, I-81) and starts GD threads “why do we allow jews to live?” and “kiddie porn: it’s what’s for breakfast” and pit thread “The mods can kiss my ass: instructions for building a pipe bomb”. Joe Dix would be banned as soon as an admin could get online.
Months later, someone else from State Tech Community College happens upon the SDMB and happens to use the computer Joe Dix used (or for some other reason ended up with the same IP address). Joanna Dix isn’t Joe Dix, but the IP address on her posts is the same.
IP spoofing software. Again, for example, let’s say I’m a troll and my IP address is 123.456.789.0. I spoofe it to be 456.789.012.3. Next time I come online I spoofe it to be 789.012.345.6. A third time I spoofe it to 098.765.432.1. This has stopped being an effective method of hiding IP addresses, though, IIRC.
As Mighty_Girl said, it’s a lot easier to spot a troll/returning banned poster by the material (or lack thereof) in their post(s). There’ve been times where I went strolling through GD (MPSIMS, IMHO and the Pit were all basically asleep;)) and saw an OP that went on for pages upon pages. Within about three sentences I knew who it was by the style and substance of the OP. Once you see the same person back again (sometimes even with a similar username … coppernissan72, goldcadillac94, etc) the third or fourth time, it becomes a question of when an admin is going to get online and find out “Oh, this person is back again … or rather, was. Hello, ReturningTroll. Goodbye, ReturningTroll.”
Also many (most) dial up systems have dynamic IP addresses. If you disconnect and reconnect chances are very good you’ll have a different IP.
I always pronounced his name as Bozo in my head, I found most of his posts I read quite amusing.
Like punha said, the people who don’t get the hint and keep trying to come back (hobbies-get some. please) usually give themselves away. Distinctive writing styles, familar arguments…
Just click the “report this post to a moderator” button and say why you think this may be a troll/returning sock. You can also email Tuba and Lynn. Don’t feed* the freaks.
I’ll raise my hand again and mention he is most likely the alter-ego of someone on the boards who we all know and love…it’s not wholly incomprehensible. When he’s tired of being a complete raving lunatic, or when his HALDOL wears off or kicks in as it may be, he’ll leave his fugue state and be just fine…
IP spoofing wouldn’t work since you need a valid IP that you control in order to initiate a connection over TCP/IP. If your on a dynamically allocated ISP, they can ban the entire subnet and not let anybody from your ISP through. Another way to stop trolls if it gets really bad is to require a unique email and to not allow the common, free email servers. ie: Yahoo, MSN etc. That way, for each new username, you need another valid email address and not many people are able to lay their hands on an infinite amount of email address.
With AOL you can have up to 7 different usernames (email addresses) - since only one is the master account, you can change the other 6 usernames (emails) as often as you like.
And don’t forget NetZero, HotMail, Juno, YaHoo, etc… e-mail domains.
They’re free. (for e-mail, anyways…)
I know, NoClueBoy, but I was responding to this quote from Shalmanese:
Oops, I misread what Shalmanese said. But, how would you determine if it isn’t say, a family member or roommate getting their own account with their own e-mail, ISP, yada yada?
I really don’t want to be defender of the weak here, particularly since there’s few things I like better than giving annoying people a kick in the pants, but why do we accuse the guy of continual drive-bys while at the same time taking pot shots ourselves?
Is there an intentional irony here?
Is it fight fire with fire?
Or does he deserve it that much?
You could also register a domain name. I can be e-mailed at any address to any of three domains. I could make up a new e-mail address every time I e-mailed anyone, if I wanted to. I don’t, though.
punha, IPs only go to 255.
I saw something inappropriate from bz0000000000000000 somewhere. can’t remember what or where.
And British posters dream in colour. Anything else just won’t do!
And now that I think about it - I am happy that there must be worse people on the SDMB than me! I have never been banned.
FTR - just in case there’s any confusion - when Michael Masterson returned with a new username, it was not as a sock; the unbanning and name happened together, as was also the case with another poster who posted under a new name after his unbanning. Think of it as the SDMB admins version of the witness protection programme.
That’s a very interesting statement…Why would you think that? Unless it’s your guilty conscious talking for you…
Where were you when BZ00000 was banned???
Are you trying to confess?
Damn. Now I’m going to have to check out all his posts for misogynistic comments.