Online Anonymity

If you are worried about your privacy online then I think it's time you learned some home truths so sit down and read this no-nonsense basic lesson in how the Internet actually works.

First of all we need to cover one thing, the difference between the World Wide Web and the Internet.  Put simply the Internet is the hardware, the physical connections that make up the network of computers that spans the globe.  The World Wide Web is an application that runs on that hardware.  There are other applications too but right now they aren't important.

When you visit a website a connection is made between your computer and the server that is hosting the website [the computer the website is saved on].  We call your computer the Client, and we call the Server - simply the Server.

You have control over anything that runs on your computer.  You do not have control over anything that is running on the server.  A lot of people are concerned with online privacy and in particular "Tracking" which keeps records of sites you visit etc.  Most of this tracking software runs on your computer Client Side.  You can disable it by installing an app or a plugin or an extension in your browser, e.g. Do Not Track, AdBlock Plus and NoScript among others.  All this is quite useful.  You can not however block anything that runs server side.  More than that you can't stay anonymous online - forget what anyone has told you its just not true.

The Internet is a vast network of computers.  They talk to each other in their own language.  That language is called a Protocol and the main one we use is called TCP/IP.  Every device that wants to use the Internet first needs an IP address.  Your computer will have an IP address, usually a local IP address that is unique to your computer within your own local network.  In most situations this network starts and ends at your router - the device that connects you to the wider internet and lets you access websites.

Your Router will have its own IP address which will be unique within a larger network which will be run by your Internet Service Provider let's say BT or O2.  At the end of that network there will be another device like a router that connects that entire network under one IP address to another larger network, until eventually at the very end there is one single network which has connections to all computers in the world through different routes through different networks.

Now, in order for information to get from your computer to the web server and back a lot of information is needed:

- Your IP address
- Your local exchange
- Your ISP
- Your Country

Among others, this information is needed in order for a connection to be made  without it you can't make a connection.  It's like making a telephone call, you need to know the telephone number to be able to call it.  None of the above information can be blocked client-side. 

A Proxy server is a computer that sits in between you and the Web server, so the Web server sees the IP address of the Proxy server instead of yours.  The proxy server then sends and receives data to and from the Web server.  It sends copies of that data back to you and asks you what to do with it.  In effect this is like you sitting in my bedroom and me talking to someone on the phone, pretending to be you, occasionally stopping to ask you questions I don't know the answer to.

Some see Proxy servers as a solution to Online Privacy, but the reality is that they bring new problems for a start, can you trust me?  I will hear everything you say to one another and have the potential to remember it, so when the person on the phone asks me for your credit card number and you tell me it after telling the person on the phone I could keep a copy of that information to myself, and I could use it later without you knowing.

Not all proxy servers are anonymous.  All connections send information back and forward including routing information and destination information.  Not all Proxy servers strip this information, some Proxy servers will actually tell the website you are visiting that the connection is via proxy and on request tell the web server your actual location - if you have ever sued a Proxy server to try and watch Hulu.com from outside the US or iPlayer from outside the UK you probably have already experienced these sites telling you they know you are not in either of those countries.

More than all of this most public access proxy servers even those that are anonymous will be listed in numerous places online and in some cases "Blacklisted".  Any website has the capability to access these lists and quickly determine that you are using an anonymous proxy and they can then deny you access to the site.

The simple truth of the Internet is that if you want to remain completely anonymous then don't use the Internet, because no matter what you do, information can and will still be gathered.  Web servers that work in co-operation can share server side data including how often you visit, the more people start using client side tools to block tracking the more websites will use Server side tools that can't be blocked.

Web sites still know what you are doing.  To give an example, on average around 1,000 of my blog visitors use AdBlock Plus to disable Google Analytics tracking code.  However I still know when you visit how long you stayed what OS you are using which Browser and which country you are in - why? I know because all of that information is shared with the web server and is required for the connection:

- When you visit is determined when you make a connection to the server
- How long you stayed is determined by the time-out of the TIME_WAIT connection your browser establishes and maintains as long as you continue to view the page and terminates when you leave.
- What OS you are using which is determined by information the browser provides but can reasonably be obtained from your TCP packets as well
- Which Browser - as above
- Which country you are in which is determined from the host-names and DNS resolution of addresses contained within the routing information necessary to deliver the web page from the server to you