Chatbots and AI-generated search summaries which are rapidly transforming the way people get their information " both use Wikipedia as a key source. Now, we can reveal Wikipedia has been subject to shady, paid-for edits ordered by partners at an elite London PR firm with links to Downing Street. And the clients who benefitted from this "wikilaundering" are some of the world's richest and most powerful people. The firm in question is Portland Communications. And it has been busted once already for this practice. After the firm was exposed, former employees told us, it simply started hiring middlemen instead. As one of them put it: "No one said, 'We should stop doing this.' The question was how we could keep doing it without getting caught." Portland's subcontractors have ... obscured mentions of a major terrorist-financing case involving Qatari businessmen; scrubbed evidence that a billion-dollar Gates-funded project failed in its mission; and promoted one side of Libya's post-Gaddafi government over the other. Often, however, their changes were more subtle: burying bad press under descriptions of a client's philanthropic work or swapping out critical news references with something more positive. "Small Wikipedia edits punch above their weight," explained Alberto Fittarelli ... at the University of Toronto's Citizen Lab. "Small, incremental changes are likely to stick for longer. These kinds of edits make narratives seem credible precisely because they are hardly noticeable. Once that enters the information stream, it becomes really hard to claw it back."