I'm curious to know, how can you tell if someone is using multiple accounts/usernames to post, assuming he/she is posting from the same computer? Can the administrators trace them to the same registration source?

yes

admin can trace email addresses and IP's

If they both posted under my forum and I checked their IP's and ran them against each other, and they were the same or very similar, then I would suspect their being one and alike. I don't usually do that, though, because most of the multiple users ever post under scifi anyway:p

i can do that????

What if, like me, you have a dynamic IP address that changes everytime I go online???

Your's doesn't change everytime you go online, only the last 3 digits of it do (or last 1 to 3, the number of characters can be 1, 2, or 3).

You have a subnet (or Subnet Mask) for your specific area (like the DNS for your ISP around Liverpool England, or where ever it is you like in the UK). There's also a gateway.

That's why things can vary easily from place to place. That's like comparing IP addresses in San Diego and LA, they are 2 different cities in California, they will have different numbers within the starting fields (assuming there is a server for each city, and that they aren't routed to the same DNS - I can't imagine that not being true for such big cities in California for example, with San Fransico, Sacramento, etc....)

Also, if someone is behind a Proxy, you'll never be able to get their IP unless the owner of the Proxy decides it wants to give it up (which it is not likely they'll do). You'll be able to get the Proxy address, but you won't be able to do much with it (you could ban the Proxy, but you could risk banning other people who use the same Proxy).

Static IP addresses are generally only used in LANs, T1 connections, etc.... Big company and mainframe stuff; most home users, even those with cable and ADSL, have dynamic addresses.

Furthermore, you can always be caught doing something unless you spoof your IP. Because they can trace the time of the attack (like 7:52 PM Pacific Standard Time) back to who held that specific dynamic IP (the last 3 digits) at that point in time when they were online.

Ok then, tell me this

Why does my IP address look different everytime I log on then, I check it everytime!! Its completely different!!

I've heard that it is almost unique to my Broadband supplier (NTL) and another supplier which I can't remember its damn name :mad:

Are you sure it is your IP address you are looking at? And not your dial in number, or some other number? And are you sure that all of the digits are different - and not only the last set?

I'll make a record of them everytime I go online