Most of the coverage of the Russian interference in the 2016 presidential election has concentrated on who did it, and for whose benefit. But there is a sense in which this was not news. Anyone who has paid attention to the story, which has been hard to avoid, already believes that the Russians did what they could to get Donald Trump elected.

The detail of what was done has been less examined. The 37 pages of Robert Mueller’s indictment contain a meticulous account of the workings of a really professional propaganda or lobbying organisation. The “Internet Research Agency” in St Petersburg is more generally known as the Russian “troll factory”, but it spent its multimillion-dollar budget on much more than simple trolling. Women operatives were sent around the US to gather intelligence and to make contact with social and political activists. It was from American political activists that they received the advice to target “purple” swing states, something that was essential to the ultimate success of the campaign.

Back in St Petersburg, there were departments for data analysis, search-engine optimisation, IT, and graphics, as well as the keyboard warriors who formed the shock troops of their assault on American politics. The indictment claims there were 80 full-time employees working on social media accounts, all pretending to be US citizens and using VPN technology to appear to be posting from inside the US. In St Petersburg they worked shifts that were designed to simulate time zones in the continental US and kept up with American public holidays. They concentrated on Facebook, where they set up groups with names designed to exploit and inflame the divisions in US society, so that “United Muslims of America” and “The Army of Jesus” were both Russian front organisations.

All this must be shocking to anyone unaware of all the ways in which Facebook and other social media platforms can be exploited. Whether the news should shock us is another and more sobering question. Social media offer advertisers and lobbyists unparalleled ways to spread their messages. Some of the most effective, as the Russian campaign shows, do not even appear as advertisements at all. This makes them all the more effective, just as propaganda presented as news is much more powerful than when it’s presented as opinion. When we ask why the Russians were able to do this, the obvious answer is that they could because anyone can. The great duopoly of Facebook and Google are the largest and most powerful advertising agencies the world has ever seen and they will sell their services to almost anyone.

The most disturbing question that the detail of the indictment raises is not whether the Russians did what is claimed but who else has been running similar campaigns. Domestic pressure groups such as the NRA, big oil and big tobacco have used astroturf groupings for decades now, and have also deliberately spread confusion about acknowledged facts. In fact they have improved on the Russian playbook by making open campaign contributions to useful politicians. The advertisements that the Russians placed on Facebook were absurd but they were effective only because hundreds of thousands of Americans said such things without being paid. The real shock of the Mueller indictment is not that the Russians exploited huge weaknesses in the American political system – what else would a hostile power try to do? – but that the weaknesses existed and are now so easy and relatively cheap for anyone to exploit.