UK Biobank data from 500,000 volunteers appeared in Alibaba listings. UK Biobank holds de-identified health data for 500,000 participants. Data supported 18,000 peer-reviewed papers on cancer, dementia, Parkinson's. Authorities removed Alibaba listings and revoked access for three institutions. CEO apologized, stating data lacked personal identifiers like names or NHS numbers. Liberal Democrats called incident a 'profound betrayal'. £200 million taxpayer funding was cited in the breach