Sources: Cambridge Analytica said it had completely wiped Facebook user data in 2016, which may be true, but it retained models derived from that data into 2017
and what Mark told Congress. @facebook : We remain determined to audit Cambridge Analytica so we can confirm what data they still have - and we're working with the UK Information Commissioner to make sure that happens. Paul Lewis / @paullewis : The Guardian has obtained emails that raise questions about the accuracy of testimony Mark Zuckerberg gave to the US Congress about Cambridge Analytica. http://www.theguardian.com/... Bruno J. Navarro / @bruno_j_navarro : Facebook's failure to compel Cambridge Analytica to delete all traces of data from its servers - including any “derivatives” - enabled the company to retain predictive models derived from millions of social media profiles throughout the US election http://bit.ly/2rpIEjL Paul-Olivier Dehaye / @podehaye : FB's CTO played the same semantic tricks (maybe even more obvious) in his @CommonsCMS testimony, answering questions of Jo S. cc @DamianCollins @carolecadwalla http://twitter.com/... David Carroll / @profcarroll : New emails reveal how Cambridge Analytica kept Facebook data models through US election into 2017. Has Facebook been truthful to Congress and Parliament? http://www.theguardian.com/... Sandy Parakilas / @mixblendr : This is a hugely important court win by @profcarroll. Now all US citizens can request their Cambridge Analytica data files — which will help figure out what exactly they were doing, where they got their data and how it might have been used. http://twitter.com/...
Context & Ripple Effects
The story so far: the March reporting established that Cambridge Analytica built psychological profiles of US voters from tens of millions of harvested profiles, and the company's defense was that its voter models no longer needed Facebook data at all — a claim it made when it said it did not use Facebook data in its voter profiles. Facebook then moved to audit the firm, but its hired forensics team had to stand down at the UK ICO's request, leaving the audit stalled.
Today's Guardian emails cut underneath both positions: Cambridge Analytica told Facebook it had wiped everything in 2016, yet apparently kept the predictive models derived from that data into 2017 — which makes 'we don't use your data' technically true while the value extracted from it persisted, and puts Mark Zuckerberg's congressional testimony about deletion under direct question.
First-order effects
- Zuckerberg's sworn statements to Congress are now contestable on their own terms: if deletion representations covered only raw data and not derivatives, lawmakers can press him on what 'deleted' actually meant.
- Facebook's stalled audit becomes more urgent rather than less — the company says it remains determined to audit Cambridge Analytica with the UK Information Commissioner precisely because it cannot confirm what survives on the firm's servers.
Second-order effects
- Former FTC officials had already flagged possible violation of Facebook's 2011 privacy consent decree; evidence that deletion promises were satisfied in name only gives US regulators a concrete lever against both Facebook and Cambridge Analytica.
- David Carroll's court win letting US citizens request their own Cambridge Analytica data files turns individual users into auditors of record — every file returned either corroborates or contradicts the wipe claim.
Third-order effects
- If 'deletion' obligations extend to models trained on harvested data rather than just the underlying records, consent decrees and regulator audits will have to inspect trained artifacts — a structural shift in what privacy compliance even means.
- The pattern points toward cross-border enforcement friction becoming standard: the ICO's ability to pause Facebook's forensic audit shows national regulators, not platforms, now control the tempo of data-scandal investigations.
The trend: Privacy enforcement is moving from verifying that raw user data was deleted to interrogating the models and derivatives built from it, where the real residual value sits.