So, should you be concerned about privacy when you visit here? No. However, every webserver on the internet (including the ones hosting this site) can gather the following information about you:
This is just a bare minimum. Most webservers can also:
Are these privacy concerns? Not really. This data can only be used for statistics unless it can be tied to an individual, or an individual's computer. However, this is a hard thing to do because of something called DHCP (Dynamic Host Configuration Protocol). All ISPs assign a DHCP or Static IP address to the computers that connect to them. By far, DHCP is used more often because it allows a server to assign an addresss to a computer whenever it needs to. Static IPs are mostly used for webservers because DNS servers need to know where to redirect traffic.
Things get even more muddled when we consider the private IP address space and Network Address Translation (NAT). Private IP addresses, such as 192.168.0.1 are used in local area networks (LAN). A LAN at a large company or school might have hundreds of computers all sharing a broadband connection. When one of these computers accesses the internet, a router uses NAT to translate the local IP to the connection address assigned by the ISP. As far as anyone on the internet can tell, those hundreds of computers might be only one or a thousand.
So what does all that mean? The data that's gathered during normal webserver operation can't be easily used to gather personaly identifiable information about anyone. The data is too vauge, it changes often (you'll usually get a different IP addresses from your isp when you connect, be it dialup or broadband), and frankly - it isn't very useful.
This doesn't mean, of course, that personal information can't be found out about individuals. Malicious code can be inserted into webpages, usualy in the form of ActiveX, java or javascript; and hackers and spyware can also be problems. Furthermore, if you do something illegal, you can be traced backwards with computer logs to your ISP; which does have your personal info.
Bottow line, I value my privacy online and I have no wish to deprive anyone else of that.