The good people at SiteMeter even give a precise account of what page you were on before you came here; more specifically which link brought you to this page. This, combined with knowledge of roughly where the person lives, can allow someone to get a good idea of who the person visiting might be, what was going through their mind when they entered the site, and possibly some insight into their browsing habits.
This kind of surveillance is quite disturbing. It may be harmless for me to discover that 35% of people visiting here use Firefox (good for you by the way; it’s heartily recommended by Stephen Fry), but just imagine what a corporation like Google or Amazon could do with more computing power and more access. In a very real way websites already access what’s on your hard drive through data files called ‘cookies’ which store the information of your doings on a particular website so that when you return the site knows who you are. The site uses these cookies which are stored in Temporary Internet Files on your hard drive; so it reaches in and has a look.
Nowadays there are all the CCTV cameras, security doors, and constant surveillance watching us outside as well as this intrusion on our privacy while simply sitting at home and using a computer. If someone came up to your window and peered in at what you were doing, you’d be entitled to call the police. Yet this kind of internet intrusion has always been there, in the background, and so no-one thinks of it as an intrusion on rights. When do we agree to this surveillance in exchange for the benefits of accessing a world-wide information network? And at what point does the exchange become uneven?
John Stuart Mill wrote extensively on the idea of freedom and a central tenet of political liberalism is his ‘harm principle’ which broadly states that one is free to pursue any action as long it doesn’t negatively affect any other person. This kind of internet surveillance is therefore justified in as much as it doesn’t harm anyone. SiteMeter can be free and accessible because there is still a degree of anonymity and it doesn’t harm the visitors to a site other than providing information they may not know (or care) is being provided. While the intrusion may be justified to some extent by reason, it doesn’t necessarily match our intuitions: there’s still the vaguely unsettling notion of being watched on any website one visits.
The moral issue comes down, as so many things do, to the permanent internal human struggle that divides all of us; reason vs. intuition: the dichotomy that has coloured all of human civilisation.