IP != end user

[ZiNgA BuRgA]

I don't get why so many stupid forum admins think that an IP is somehow representative of a user.  In fact, this extends to stuff like spam control, like StopForumSpam, or Cloudflare, or whatever system relies heavily on a blacklist of IP addresses.

An IP does not represent the end user
There are many things to consider:

• School/college/corporate networks often use a single public facing IP
• Public computers or wireless hotspots may also use a single IP
• ISP transparent proxies - some ISPs redirect TCP port 80 traffic through a transparent proxy, meaning a limited number of front facing IPs across the ISP
• Dynamic IPs - quite common
• IPv4 exhaustion - a problem which is only going to get worse considering that IPv6 still has pretty much no support; I believe ISPs in Asia are already deploying ISP level NATs (on top of dynamic IPs)
• Multiple people living in the same house or accommodation building
• Zombie computers or hijacking neighbour's wifi
• Oh, and of course, heaps of proxies out there...
  

Essentially, dynamic IPs and NATs/proxies.

Just felt like getting it off my chest.