On the day Boris Johnson took over as prime minister, hundreds of Facebook ads dropped like confetti into thousands of UK voters’ news feeds. Many were virtually identical, featuring a black-and-white photograph of Johnson gazing towards an unseen audience. “These are my priorities,” one version of the ad read. “What are yours?”

Quickly, the ads were interpreted as the start of Johnson’s election campaign and the splurge drew immediate parallels with the Facebook-driven 2016 Vote Leave campaign, especially since the director of that campaign – the Svengali-like Dominic Cummings – walked into 10 Downing Street as Johnson’s most senior adviser on the same day. Then on Friday we learned, through reports in the Guardian, that the political campaigning firm CTF Partners, one of whose heads ran Johnson’s leadership campaign, was running a network of unbranded “news” pages on Facebook on behalf of its clients.

The Facebook ad blitz rightly attracted media attention, but was it inherently sinister? In this particular case, there is good reason to be suspicious. Data and digital advertising were critical to the success of Vote Leave – as Cummings has told us in his voluminous blogs – yet we still know very little about what data was collected, how it was used and the role played by the uncommunicative Canadian company, AggregateIQ.

To condemn all online political campaigns ignores the extent to which digital advertising has become ubiquitous

Cummings himself has refused to appear before the Commons select committee for digital, culture, media and sport to explain what he did (and has been found in contempt of parliament as a consequence). The Vote Leave campaign has been found to have broken electoral law. And this is separate to the lingering questions about Cambridge Analytica and the referendum, rekindled by Netflix’s new film, The Great Hack. There is therefore good reason to distrust Cummings’s campaigning methods.

Yet to condemn all online political campaigns ignores the extent to which digital advertising has become ubiquitous since 2016. The Conservatives may be spending lots right now, but every major party is ploughing money into Facebook, Instagram, Snapchat, Google and YouTube. According to the Facebook ad archive, Labour has spent £175,000 since last October, the Liberal Democrats £288,000 and the Brexit party £190,000. And this is just on Facebook and does not include what they spend on other digital platforms, email campaigns or on data collection and analysis.

Nor is it just the political parties – non-party campaigners, NGOs and individuals are all using digital platforms to push their messages, as are People’s Vote, Best for Britain, Britain’s Future and the London mayor. Similarly, Friends of the Earth, Liberty, the RSPCA, Greenpeace, 38 Degrees and other charities are using social media to raise awareness of issues such as the climate crisis, human rights and dog care. There is even a site called ScramNews using Facebook ads to raise money to pay for anti-Brexit-party ads – on Facebook.

If you want to push a message, why not use the cheapest, most effective way to mobilise your target audience? Using television news would, by comparison, seem bizarre and anachronistic. Britons aged 16 to 24 have deserted traditional news outlets, we discovered recently from Ofcom research. They now watch, on average, only two minutes of TV news a day, as compared with the over-65s who are still watching over half an hour. Most young people get their news online, chiefly via social media. Any campaigner who does not try to reach young people via their phones is unlikely to last very long in campaigning.

But until recently we could not see what candidates and parties were promising on Facebook. We did not know if the promises they made were true, false, distorted, contradictory, defensible or unethical. Now each of the major platforms keeps archives of political ads so we can look at who is targeting what at whom. There is still a lot to be done to improve the archives, as seen by a recently published Mozilla report, but we are far better off than in 2016.

Given the ubiquity of online political advertising and its growing transparency, there is a temptation to think we should stop worrying and accept it as a fact of digital life. This would be a mistake. Why? Because there are still huge gaps between the laws and regulations that protect elections and referendums in the real world and those that apply online. And, as the Guardian investigation into CTF Partners shows, digital propaganda keeps evolving.

Take transparency. Online, there are still untold opportunities to run dark campaigns with funding from who knows where. We still do not know the source, for example, of the £435,154 that a company called Britain’s Future has spent on pro-Brexit Facebook ads since last October. We are only now discovering that this was one of a number of political “Astroturf” campaigns managed covertly by Lynton Crosby’s CTF partners, campaigns that deliberately blurred political advertising with unbranded “news”. Should there be an autumn election, you can be sure there will be many pop-up campaigns, with tailored “news” promoted through hundreds of online ads, whose sources of funding will be unknown.

At any future election, the political parties will use Facebook’s tools to target adverts at carefully selected susceptible voters in marginal constituencies. They will, just as Cummings has told us Vote Leave did in 2016, bombard these voters with pre-tested messages and we will not know how they select these voters or how they adapt their messaging based on the responses.

And though they will spend significant amounts on a small number of voters in a select group of constituencies, it is highly unlikely any of this money will be allocated to the constituency itself. This will not even be against the law.

Political advertising online may now be integral to any modern campaign, and it is becoming more open and familiar, but there is still much that must change before we can stop worrying. Yet, with Cummings and the Vote Leave team installed in No 10, and an autumn election likely, chances of electoral reform are slim to nonexistent.

• Martin Moore is the author of Democracy Hacked: How Technology is Destabilizing Global Politics and a senior lecturer at King’s College London