NEW coloured statuses have been rolled out across Facebook. Now, instead of just posting your thoughts, you can choose a coloured background graphic for the text to sit on. It seems harmless enough, so why do I find myself wondering, every time I see one, what the hell Facebook's up to now?

The reason is because I understand that my behaviour, my "data", is now big business. A tiny number of tech giants, like Facebook, Google and Amazon, are among the biggest and most powerful companies in the world because of people like you and I, and most of us don't really get it.

My mind keeps flitting back to the time Facebook conducted secret mood experiments by manipulating the feeds of a select number of users to see what effect it had on their behaviour. What had previously seemed like a harmless trade of data between CEO Mark Zuckerberg and I when I use Facebook felt a lot more sinister when I realised it was discovering the lengths to which it could manipulate human behaviour without anyone knowing.

These huge companies have growing influence over our lives, and the big problem is that nobody really understands why. Outside of my job as a journalist, nobody ever raises it with me. We're all so addicted to our services – chatting on Facebook, listening to music on YouTube, shopping on Amazon – that many of just don't care. Yet.

Here's how it works: you are not anonymous when using the internet. People need to wrap their heads around that fact. You are not faceless behind a screen that separates you from the content you're looking at. You're entirely trackable, and every click you make is monitored by sophisticated technology.

The websites you visit, the people you speak to, the things you buy, the music you listen to, the books you read, the random subjects you look up on Google out of curiosity – it's all recorded. That information, that data, is then swept up by tech giants which use it to create a profile of you that they can sell to advertisers.

It means that advertisers can target you with specific products that you're more likely to buy, which gives them the best value for money. They don't have to take out an ad in a newspaper and hope the right person sees it; they can get to the right person straight away and cut out the middle men. It has become so personal that people have commented to me that they’re sure the internet is reading their minds.

But it doesn't stop there. Targeted advertising is just as useful for political campaigners, especially rich ones. In fact, a key part of Donald Trump's campaign was a savvy use of targeted technology and use of data.

Indeed, the fake news phenomenon during the American election was only possible because of the advertising technology provided by Google and the distribution power of social networks. Tech and data have serious implications for modern democracy, yet companies like Facebook are dragging their heels on responsibility.

When you cast your mind back to Facebook's little mood experiment, it becomes a lot more frightening to realise how accessible your data is to people you don't know, and how you don't have the capacity to understand how data manipulation may one day be manipulating your own mind. The chilling likelihood is that it already has.

Furthermore, writers, academics and intellectuals who concern themselves with these things warn that the huge monopolies enjoyed by a tiny number of tech companies on the data, search and advertising arenas is as irresponsible as it gets. The vast swathes of power and money gained from such success benefits a relative few compared to the numbers of people who face unemployment on an unprecedented scale in the future as a result of technological advancements and automation. Who needs workers when you can get robots that don't want a minimum wage and decent conditions?

This massive tech sector has no real sense of social or political responsibility. It’s money-driven and chaotic, and who in politics has the will to take it on when their own success might depend on it?

That’s why, when Facebook or any of the others begin rolling out mysterious new features, we should all stop for a minute and remember the bigger picture.

This is business, and every aspect of your being is up for sale. Did you agree to it?