I know you're probably not going to read this. As a web designer I'm all too aware that people don't spend much time reading text from a computer screen. The vast majority of visitors to any web page leave again within the first couple of seconds; pages with a wall of text not done. Which means you got a problem if you happen to write a blog about a subject that involves not only giving practical advice but also lots of politics and marketing. Is it better to leave out the detail and just copy the Direct Marketing Association's propaganda (registering with the Mailing Preference Service will stop up to 95% of personally addressed direct mail), or is it better to take a more critical stance and to give comprehensive information about getting rid off junk mail?

I had to think of this while reading a lengthy article on the Wall Street Journal website about yet another Facebook privacy breach. Stopping marketing that involves chopping down forests may be complicated, it's a doodle compared to stopping online junk mailers. At least, that's how it seems to me, as someone who is really not an expert when it comes to online marketing.

What I found particularly interesting about the article is that there are many links between traditional and online marketing. Both forest-raiding and online marketers claim that the work they do is good for 'consumers'. Advertising informs 'consumers' about products and services; without advertisements you would need to make up your own mind about how to spend your money, and such a level of autonomy can only lead to confusion and depression, right?

And, both type of marketers target advertisements in ways that raise serious privacy concerns. The Facebook story in the Wall Street Journal is about applications such as Farmville that pass people's personal details to marketers. Apparently, the ten most popular Facebook apps all transmit people's user ID to junk mailers – even if you have set your Facebook profile to the strictest privacy settings. It's a breach of Facebook's terms and conditions, to be sure, and Facebook was quick to promise that it will introduce new technology to contain the problem. Yet, it happened, and without the excellent journalistic work of the Journal the breach of privacy would have continued.

The personal details marketers collected this way ended up in tens of junk mail databases. Companies such as RapLeaf link the data with other personal data obtained elsewhere on the world wide web, and sell it numerous other marketers. The name of the product that is being sold is called 'targeting' – nowadays the magic word in Marketing Land. To 'target' you need to find out as much as possible about the objects you're targeting. And so every time you click one of those new 'Like' buttons on Facebook you tell junk mailers a bit more about yourself. If you think it's just about sharing what you like with friends, think again.

Old fashioned marketing is not much different. Using socio-economic data on postcode level is no longer good enough. In order to bring you the junk mail you really want marketers need to know what you buy and where; which websites you visit; what books you're reading; which charities you're a member of; how often you pick your nose; who you slept with last night; and god know what else. In order for junk mail to become better targeted ever more personal information needs to be stored (and kept up to date) on databases run by anonymous people who work for companies you've never even heard of, and never will.

Some practical advice then? Firstly, a good guide to stopping Facebook from sharing your personal details with junk mailers third parties can be found on gawker.com. Secondly, Firefox's Adblock Plus add-on is probably the most effective add-blocker around and will get rid off any Facebook advertisements.