A few years ago, it cost me 69p a year to use WhatsApp – and what a bargain that seemed.

As a student, I remember paying 12p per text message using an old Philips BT Cellnet brick. Send six WhatsApp messages and you’ve already come out ahead!

It may only have cost around the price of a pint of milk, but it still felt like a triumph when it was announced in 2016 that there would no longer be an annual fee for using the messaging app. We love a freebie in this country: present me with a plate of sandwiches and I’ll scoff the lot, regardless of when I last ate.

However two years before alarm bells had started ringing when Facebook acquired WhatsApp for $19 billion, with many fearing the social media giant would assimilate data from the messaging platform into its own and build an even more comprehensive picture of us all individually.

Indeed in 2016 Facebook announced an intention to tap into WhatsApp’s records in order to improve its friend suggestions and targeted advertising. That was halted by the Information Commissioner’s Office, which opened a full investigation and ruled earlier this year that sharing of data between the companies would be illegal.

So if Facebook can’t make use of WhatsApp’s data, what other plans did it have to monetise it? There was a clue last September when WhatsApp co-founder Brian Acton left the company to start a foundation – and got involved in the #deletefacebook movement following the Cambridge Analytica scandal.

And when the other founder of the company, Jan Koum, quit this week amid reports that he disagreed with Facebook over the potential introduction of ads on to the platform, it jumped right back into the public eye.

Facebook CEO Mark Zuckerberg said he was grateful to Koum for teaching him about “encryption and its ability to take power from centralised systems and put it back in people's hands… those values will always be at the heart of WhatsApp”.

But do we believe him? Zuck obviously has Facebook’s domination of communication close to his heart, given the acquisition of Instagram and attempts to buy Snapchat. The truth is Facebook owns most of the platforms we use, from Messenger to Insta and WhatsApp.

The latter is now as ubiquitous in our lives as Facebook itself thanks to group messaging: we use it to communicate regularly with family and friends, and it has well over a billion active daily users. There aren’t really any viable alternatives to WhatsApp and Messenger, unless you are conversing with a niche group of friends.

I worry that should ads be introduced, the erosion of our privacy within the encrypted messaging app could follow. I already put up with cold calls on a weekly basis despite being extremely careful about who I share my phone number with. Will WhatsApp share my number with third parties in future?

The horse has bolted, but perhaps these platforms shouldn’t be free at all. If we had paid for them from the outset, perhaps those who ran them would have done more than paid lip service to our privacy while keeping shareholders content.

How much would you pay to use WhatsApp, Facebook and the rest to protect your data? 91 per cent of people who responded to a poll I put out on Twitter yesterday would be willing to pay something. 

Watching my kids grow up into an increasingly connected world, even £69 a year now seems a small price.