When you ‘like’ something on Facebook or read an online newspaper, perhaps a dozen or more companies are squirreling away data on your tastes, your habits, whether you’re male or female, old or young, gay or straight.

They mean no harm. They just want to give you, the customer, exactly what you want - it’s the grandfather of all business slogans. Their dilemma, now regulators’ noses are twitching, is how to serve you, and serve themselves, when what you want is to be left alone.

There are thousands of analytics companies, audience targeters, ad brokers, ad exchanges and the like that can collect and sell data-based services on internet users for 5,000 euros a time to big brands, which then buy ad space where their potential customers might be lurking.

You only know these trackers are at work if you read the fine print. The New York Times has a disclaimer saying it hires WebTrends and Audience Science to interpret its readers’ interests, and Britain’s Guardian newspaper says it pays Criteo and Quantcast, among others, to do the same.

READ MORE: Web privacy rules turn poachers into gamekeepers